int fallbacks for int ops

all chapters, a little sharper for int ops

80 files changed, 245 insertions, 128 deletions

diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/AddNode.java
index f568416c..0291a900 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -23,7 +23,7 @@ public class AddNode extends Node {
                 return TypeInteger.constant(i0.value()+i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index af0d22b7..143a6fde 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -29,7 +29,7 @@ abstract public class BoolNode extends Node {
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
index c7276710..bffa4b44 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -25,7 +25,7 @@ public class DivNode extends Node {
                     : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index b83c41a5..ad6e513a 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -18,7 +18,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 68ba9025..60103b8b 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -23,7 +23,7 @@ public class MulNode extends Node {
                 return TypeInteger.constant(i0.value()*i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 83c63244..6a56ff64 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -18,7 +18,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
index c12e7388..f5ad663d 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -27,7 +27,7 @@ public class SubNode extends Node {
                 return TypeInteger.constant(i0.value()-i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/README.md b/chapter05/README.md
index 7337da33..2732066e 100644
--- a/chapter05/README.md
+++ b/chapter05/README.md
@@ -83,6 +83,10 @@ one for each of the control inputs to that `Region`.  The result computed by a
 control input to the `Region` can be active at a time, and the `Phi` passes
 through the data value from the matching input.[^1]
 
+Its type is the meet of its data-input types. Two different integer constants
+merge to `TypeInteger.BOT`: the value is unknown, but it is still an integer.
+Integer arithmetic likewise retains an integer result type when it cannot fold.
+
 #### `RegionNode`
 
 In this Sea of Nodes, there is an embedded Control Flow Graph - and like a
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 0600222a..2772c4c5 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -23,7 +23,7 @@ public class AddNode extends Node {
                 return TypeInteger.constant(i0.value()+i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index f5db6574..87acc6cc 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -29,7 +29,7 @@ abstract public class BoolNode extends Node {
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 1bb04be7..f80f092d 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -25,7 +25,7 @@ public class DivNode extends Node {
                     : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index b83c41a5..ad6e513a 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -18,7 +18,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 46ee6058..b1d9e44a 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -23,7 +23,7 @@ public class MulNode extends Node {
                 return TypeInteger.constant(i0.value()*i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 83c63244..6a56ff64 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -18,7 +18,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
index 95c0fdf9..b3b5462d 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/PhiNode.java
@@ -24,7 +24,10 @@ public class PhiNode extends Node {
 
     @Override
     public Type compute() {
-        return Type.BOTTOM;
+        Type t = in(1)._type;
+        for( int i=2; i<nIns(); i++ )
+            t = t.meet(in(i)._type);
+        return t;
     }
 
     @Override
diff --git a/chapter05/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter05/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 2e170273..d3fd1c7e 100644
--- a/chapter05/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter05/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -27,7 +27,7 @@ public class SubNode extends Node {
                 return TypeInteger.constant(i0.value()-i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 1cc20608..72dc0ffd 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -23,7 +23,7 @@ public class AddNode extends Node {
                 return TypeInteger.constant(i0.value()+i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 24bca613..ab1b474c 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -29,7 +29,7 @@ abstract public class BoolNode extends Node {
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 1bb04be7..f80f092d 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -25,7 +25,7 @@ public class DivNode extends Node {
                     : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index b83c41a5..ad6e513a 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -18,7 +18,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 20ec7d87..380cb042 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -23,7 +23,7 @@ public class MulNode extends Node {
                 return TypeInteger.constant(i0.value()*i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 83c63244..6a56ff64 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -18,7 +18,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 2e170273..d3fd1c7e 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -27,7 +27,7 @@ public class SubNode extends Node {
                 return TypeInteger.constant(i0.value()-i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/AddNode.java
index f80467b9..84367cc7 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -25,7 +25,7 @@ public class AddNode extends Node {
                 return TypeInteger.constant(i0.value()+i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 3938b903..f5bbc9ad 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -31,7 +31,7 @@ abstract public class BoolNode extends Node {
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/DivNode.java
index e8b7067e..f71a32db 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -27,7 +27,7 @@ public class DivNode extends Node {
                     : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index e4d718d5..9d3d3f5d 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 18e23d8b..4884ee18 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -25,7 +25,7 @@ public class MulNode extends Node {
                 return TypeInteger.constant(i0.value()*i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/NotNode.java
index e8d2ecf2..4c0be167 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -20,7 +20,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter07/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter07/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 5e61df95..1ab17b04 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -29,7 +29,7 @@ public class SubNode extends Node {
                 return TypeInteger.constant(i0.value()-i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 7fa63426..fa3a6169 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -25,7 +25,7 @@ public class AddNode extends Node {
                 return TypeInteger.constant(i0.value()+i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 3938b903..f5bbc9ad 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -31,7 +31,7 @@ abstract public class BoolNode extends Node {
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/DivNode.java
index e8b7067e..f71a32db 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -27,7 +27,7 @@ public class DivNode extends Node {
                     : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index e4d718d5..9d3d3f5d 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 18e23d8b..4884ee18 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -25,7 +25,7 @@ public class MulNode extends Node {
                 return TypeInteger.constant(i0.value()*i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/NotNode.java
index e8d2ecf2..4c0be167 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -20,7 +20,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter08/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter08/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 5e61df95..1ab17b04 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -29,7 +29,7 @@ public class SubNode extends Node {
                 return TypeInteger.constant(i0.value()-i1.value());
             return i0.meet(i1);
         }
-        return Type.BOTTOM;
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 557fb451..b57b305f 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -19,12 +19,16 @@ public class AddNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()+i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 2000e905..08ff3789 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -25,12 +25,16 @@ abstract public class BoolNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/DivNode.java
index d6ecfb69..6cee90ad 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -19,14 +19,18 @@ public class DivNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return i1.value() == 0
                     ? TypeInteger.ZERO
                     : TypeInteger.constant(i0.value()/i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index cb79b15b..5b055089 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 6a6c82f9..97721ce3 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -19,12 +19,16 @@ public class MulNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()*i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 9fce01bd..a9a69c59 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -20,7 +20,7 @@ public class NotNode extends Node {
     public Type compute() {
         if( in(1)._type instanceof TypeInteger i0 )
             return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter09/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter09/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 20c7e1cb..59cd31f0 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -19,16 +19,20 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
         // Sub of same is 0
         if( in(1)==in(2) )
             return TypeInteger.ZERO;
 
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()-i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java
index b88e13b5..de5044d7 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -19,12 +19,16 @@ public class AddNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()+i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index ab577aa6..bf0d3a84 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -26,12 +26,16 @@ abstract public class BoolNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java
index d6ecfb69..6cee90ad 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -19,14 +19,18 @@ public class DivNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return i1.value() == 0
                     ? TypeInteger.ZERO
                     : TypeInteger.constant(i0.value()/i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index fa252903..8b1b73bf 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 6a6c82f9..97721ce3 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -19,12 +19,16 @@ public class MulNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()*i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 3d85b220..83141836 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -33,7 +33,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 8264b740..dfb4744d 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -19,16 +19,20 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
         // Sub of same is 0
         if( in(1)==in(2) )
             return TypeInteger.ZERO;
 
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()-i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/AddNode.java
index b88e13b5..de5044d7 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -19,12 +19,16 @@ public class AddNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()+i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index ab577aa6..bf0d3a84 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -26,12 +26,16 @@ abstract public class BoolNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(doOp(i0.value(), i1.value()) ? 1 : 0);
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     abstract boolean doOp(long lhs, long rhs);
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/DivNode.java
index d6ecfb69..6cee90ad 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -19,14 +19,18 @@ public class DivNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return i1.value() == 0
                     ? TypeInteger.ZERO
                     : TypeInteger.constant(i0.value()/i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index fa252903..8b1b73bf 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 6a6c82f9..97721ce3 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -19,12 +19,16 @@ public class MulNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()*i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 3d85b220..83141836 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -33,7 +33,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter11/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter11/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 515b21e8..76a34e31 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -20,16 +20,20 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
         // Sub of same is 0
         if( in(1)==in(2) )
             return TypeInteger.ZERO;
 
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()-i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/AddNode.java
index f51adcf1..188c50a8 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -19,12 +19,16 @@ public class AddNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()+i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/DivNode.java
index ae73284f..bc9ff7d9 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -19,14 +19,18 @@ public class DivNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return i1.value() == 0
                     ? TypeInteger.ZERO
                     : TypeInteger.constant(i0.value()/i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 0f2669b9..c3be733c 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/MulNode.java
index 09a27582..9891cd45 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -19,12 +19,16 @@ public class MulNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()*i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/NotNode.java
index e987bd82..bb7e9265 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -20,7 +20,9 @@ public class NotNode extends Node {
         Type t0 = in(1)._type;
         switch( t0 ) {
         case TypeInteger i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            if( i0==TypeFloat.TOP ) return TypeInteger.TOP;
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOT;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
@@ -33,7 +35,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/SubNode.java
index c9d20ce0..d8538277 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -20,17 +20,21 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
         // Sub of same is 0
         if( in(1)==in(2) )
             return TypeInteger.ZERO;
 
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()-i1.value());
         }
 
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/AddNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/AddNode.java
index 1c4b94f8..eb1bd073 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/AddNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/AddNode.java
@@ -19,12 +19,16 @@ public class AddNode extends Node {
 
     @Override
     public Type compute() {
-        if( in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1 ) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if( t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1 ) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()+i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/DivNode.java
index ae73284f..bc9ff7d9 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -19,14 +19,18 @@ public class DivNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return i1.value() == 0
                     ? TypeInteger.ZERO
                     : TypeInteger.constant(i0.value()/i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 0f2669b9..c3be733c 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -20,7 +20,7 @@ public class MinusNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0)
             return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0;
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/MulNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/MulNode.java
index e631492c..4cd075e4 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/MulNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/MulNode.java
@@ -19,12 +19,16 @@ public class MulNode extends Node {
 
     @Override
     public Type compute() {
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()*i1.value());
         }
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/NotNode.java
index e987bd82..bb7e9265 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -20,7 +20,9 @@ public class NotNode extends Node {
         Type t0 = in(1)._type;
         switch( t0 ) {
         case TypeInteger i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            if( i0==TypeFloat.TOP ) return TypeInteger.TOP;
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOT;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
@@ -33,7 +35,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/SubNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/SubNode.java
index 467d9181..4b860c37 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/SubNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/SubNode.java
@@ -20,17 +20,21 @@ public class SubNode extends Node {
 
     @Override
     public Type compute() {
+        Type t1 = in(1)._type, t2 = in(2)._type;
+        if( t1==Type.TOP || t1==TypeInteger.TOP ||
+            t2==Type.TOP || t2==TypeInteger.TOP )
+            return TypeInteger.TOP;
         // Sub of same is 0
         if( in(1)==in(2) )
             return TypeInteger.ZERO;
 
-        if (in(1)._type instanceof TypeInteger i0 &&
-            in(2)._type instanceof TypeInteger i1) {
+        if (t1 instanceof TypeInteger i0 &&
+            t2 instanceof TypeInteger i1) {
             if (i0.isConstant() && i1.isConstant())
                 return TypeInteger.constant(i0.value()-i1.value());
         }
 
-        return in(1)._type.meet(in(2)._type);
+        return TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 27b4a478..176d2a3d 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -24,7 +24,7 @@ public class MinusNode extends Node {
             if( i0 == TypeInteger.BOT || i0._min == Long.MIN_VALUE ) return TypeInteger.BOT;
             return TypeInteger.make(-i0._max,-i0._min);
         }
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type.isHigh() ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 3ef5d19e..17b6e46e 100644
--- a/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter14/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -21,7 +21,8 @@ public class NotNode extends Node {
         if( t0.isHigh() ) return TypeInteger.BOOL.dual();
         switch( t0 ) {
         case TypeInteger i0:  return i0._max < 0 || i0._min > 0 ? TypeInteger.FALSE : (i0==TypeInteger.ZERO ? TypeInteger.TRUE : TypeInteger.BOT);
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOT;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
@@ -34,7 +35,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 7e95088f..63cfd110 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -22,7 +22,7 @@ public class MinusNode extends Node {
             if( i0.isHigh() ) return TypeInteger.TOP;
             return i0==TypeInteger.BOT ? TypeInteger.BOT : TypeInteger.make(-i0._max,-i0._min);
         }
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type.isHigh() ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 3ef5d19e..17b6e46e 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -21,7 +21,8 @@ public class NotNode extends Node {
         if( t0.isHigh() ) return TypeInteger.BOOL.dual();
         switch( t0 ) {
         case TypeInteger i0:  return i0._max < 0 || i0._min > 0 ? TypeInteger.FALSE : (i0==TypeInteger.ZERO ? TypeInteger.TRUE : TypeInteger.BOT);
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOT;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
@@ -34,7 +35,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter16/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter16/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 7e95088f..63cfd110 100644
--- a/chapter16/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter16/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -22,7 +22,7 @@ public class MinusNode extends Node {
             if( i0.isHigh() ) return TypeInteger.TOP;
             return i0==TypeInteger.BOT ? TypeInteger.BOT : TypeInteger.make(-i0._max,-i0._min);
         }
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type.isHigh() ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter16/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter16/src/main/java/com/seaofnodes/simple/node/NotNode.java
index 9e4cc324..38c6c90e 100644
--- a/chapter16/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter16/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -21,7 +21,8 @@ public class NotNode extends Node {
         if( t0.isHigh() ) return TypeInteger.BOOL.dual();
         switch( t0 ) {
         case TypeInteger i0:  return i0._max < 0 || i0._min > 0 ? TypeInteger.FALSE : (i0==TypeInteger.ZERO ? TypeInteger.TRUE : TypeInteger.BOOL);
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOT;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
@@ -34,7 +35,7 @@ public class NotNode extends Node {
             if( t0.getClass() != Type.class )
                 // Only doing NOT on ints and ptrs
                 throw Utils.TODO();
-            return t0==Type.TOP ? Type.TOP : Type.BOTTOM;
+            return t0==Type.TOP ? TypeInteger.TOP : TypeInteger.BOT;
         }
     }
 
diff --git a/chapter17/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/chapter17/src/main/java/com/seaofnodes/simple/node/MinusNode.java
index 50377061..a9e21814 100644
--- a/chapter17/src/main/java/com/seaofnodes/simple/node/MinusNode.java
+++ b/chapter17/src/main/java/com/seaofnodes/simple/node/MinusNode.java
@@ -25,7 +25,7 @@ public class MinusNode extends Node {
                 return TypeInteger.BOT;
             return TypeInteger.make(-i0._max,-i0._min);
         }
-        return TypeInteger.TOP.meet(in(1)._type);
+        return in(1)._type.isHigh() ? TypeInteger.TOP : TypeInteger.BOT;
     }
 
     @Override
diff --git a/chapter17/src/main/java/com/seaofnodes/simple/node/NotNode.java b/chapter17/src/main/java/com/seaofnodes/simple/node/NotNode.java
index cca84a2d..3f4b291c 100644
--- a/chapter17/src/main/java/com/seaofnodes/simple/node/NotNode.java
+++ b/chapter17/src/main/java/com/seaofnodes/simple/node/NotNode.java
@@ -21,7 +21,8 @@ public class NotNode extends Node {
         if( t0.isHigh() ) return TypeInteger.BOOL.dual();
         switch( t0 ) {
         case TypeInteger i0:  return i0._max < 0 || i0._min > 0 ? TypeInteger.FALSE : (i0==TypeInteger.ZERO ? TypeInteger.TRUE : TypeInteger.BOOL);
-        case TypeFloat   i0:  return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : i0;
+        case TypeFloat   i0:
+            return i0.isConstant() ? TypeInteger.constant(i0.value()==0 ? 1 : 0) : TypeInteger.BOOL;
         case TypeMemPtr p0:
             // top->top, bot->bot, null->1, *void->0, not-null ptr->0, ptr/nil->bot
             // If input in null then true
diff --git a/docs/chapter-backports.md b/docs/chapter-backports.md
index 150afe20..650d7c26 100644
--- a/docs/chapter-backports.md
+++ b/docs/chapter-backports.md
@@ -218,6 +218,7 @@ Unresolved reproductions have been promoted to the pending queue above.
 
 | Completed work | Scope and evidence retained |
 |---|---|
+| Integer result types | Integer-op fallbacks in 4-13 and remaining unary cases through 17 retain integer types; 5's Phis meet their data-input types. Full Make suites in 4-17 passed, plus a chapter 5 snapshot check of Phi/Add types. Integer BOT starts in 4; later arithmetic already has typed fallbacks, with unresolved bimorphic modes preserved in 25. |
 | B14 cyclic leaf-kind equality | 23-24 backport; 25 already correct. Cyclic equality starts in 23. `TypeTest.testCyclicLeafKinds` fails before the fix; earlier interned-child equality already checks kinds. Full affected suites passed. |
 | B13 / #246 null guards | Nested Not/null guard discovery from 10; short-circuit Phi availability in 23-24. Regression and full suites in 10-25 passed. Separate null-dereference diagnostic remains queued. |
 | B09 and #251 debug printing | Side-effect-free print/accessor paths from their first applicable chapters; `_` diagnostic naming, type interning allowed, layouts forbidden. Dead nodes use `isDead()`, not null `_inputs`, from 7. Original-printer negative checks and full affected suites passed. |
diff --git a/graph/README.md b/graph/README.md
index b98ca9d3..eb3e8d18 100644
--- a/graph/README.md
+++ b/graph/README.md
@@ -178,6 +178,15 @@ ordering are follow-up work, along with preserving positions across rewrites.
 Each visited frame currently retains a full snapshot and layout; bounded
 history, checkpoints and deltas are also follow-up work.
 
+Pending graph work:
+
+- Improve CFG placement with compiler-provided RPO and nested regions for
+  compilation units, functions and loops.
+- Preserve positions across peepholes, then animate edits and zoom into the
+  peep neighborhood before returning to the whole graph.
+- For large compilations, add checkpoints and forward deltas with a bounded
+  cache of recent backward steps.
+
 ELK runs locally from the pinned elkjs 0.12.0 worker; see
 [`web/vendor/elk-README.md`](web/vendor/elk-README.md) for provenance and licensing.
 No npm or Maven step is needed to use it.