Fix stale copy-pasted comment on BoolNode's phiCon call (#249)

The three comment lines above `AddNode.phiCon(this, ...)` in BoolNode were
copy-pasted from MulNode and never adapted: they use `*` as the operator and
describe the rotated shape `(x * (phi cons)) * con`.

For BoolNode neither is right. The operator is a compare, and in chapters
6-9 `rotate` is hard-coded `false`, so the rotated shape is never matched;
the shapes actually handled are `(phi cons) cmp con` and
`(phi cons) cmp (phi cons)`.

Reword the comment accordingly, and in chapters 6-9 add a line noting why
rotate is off. Chapters 10-25 pass `this instanceof EQ`, so no such claim is
made there.

Comment-only change; no code is touched.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

19 files changed, 61 insertions, 57 deletions

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 a9ec6838..79c65c60 100644
--- a/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter06/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -43,9 +43,10 @@ abstract public class BoolNode extends Node {
         if( in(1)==in(2) )
             return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0));
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
+        // No rotate: compares are not associative.
         Node phicon = AddNode.phiCon(this,false);
         if( phicon!=null ) return phicon;
 
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 0c32d50d..5948a1d3 100644
--- a/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter07/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -45,9 +45,10 @@ abstract public class BoolNode extends Node {
         if( in(1)==in(2) )
             return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0));
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
+        // No rotate: compares are not associative.
         Node phicon = AddNode.phiCon(this,false);
         if( phicon!=null ) return phicon;
 
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 0c32d50d..5948a1d3 100644
--- a/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter08/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -45,9 +45,10 @@ abstract public class BoolNode extends Node {
         if( in(1)==in(2) )
             return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0));
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
+        // No rotate: compares are not associative.
         Node phicon = AddNode.phiCon(this,false);
         if( phicon!=null ) return phicon;
 
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 d3fcec95..ee643bf5 100644
--- a/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter09/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -44,9 +44,10 @@ abstract public class BoolNode extends Node {
         if( in(1)==in(2) )
             return new ConstantNode(TypeInteger.constant(doOp(3,3)?1:0));
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
+        // No rotate: compares are not associative.
         Node phicon = AddNode.phiCon(this,false);
         if( phicon!=null ) return phicon;
 
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 9c15f01b..8719e4d5 100644
--- a/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter10/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -60,9 +60,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
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 9c15f01b..8719e4d5 100644
--- a/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter11/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -60,9 +60,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter12/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter12/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index a31bd963..f202b263 100644
--- a/chapter12/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter12/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -67,9 +67,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter13/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter13/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index a31bd963..f202b263 100644
--- a/chapter13/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter13/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -67,9 +67,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index aa9fd312..06c10a79 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -69,9 +69,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter16/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter16/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index aa9fd312..06c10a79 100644
--- a/chapter16/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter16/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -69,9 +69,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter17/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter17/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index aa9fd312..06c10a79 100644
--- a/chapter17/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter17/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -69,9 +69,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter18/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter18/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 83893968..dc57f7b4 100644
--- a/chapter18/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter18/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -70,9 +70,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter19/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter19/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 93e5e4e9..0d255cb2 100644
--- a/chapter19/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter19/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -69,9 +69,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter20/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter20/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index e6b87ce8..3f959e75 100644
--- a/chapter20/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter20/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -71,9 +71,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index fd6448a2..5f96c591 100644
--- a/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter21/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -71,9 +71,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter22/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter22/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 301e1517..0cf8b87e 100644
--- a/chapter22/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter22/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -71,9 +71,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter23/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter23/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 2765c308..513f8d31 100644
--- a/chapter23/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter23/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -71,9 +71,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter24/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter24/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index 2765c308..513f8d31 100644
--- a/chapter24/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter24/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -71,9 +71,9 @@ abstract public class BoolNode extends Node {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;
 
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/BoolNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/BoolNode.java
index c8722f67..ef71983e 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/node/BoolNode.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/node/BoolNode.java
@@ -102,9 +102,9 @@ abstract public class BoolNode extends Node implements ModeNode {
                 return new NotNode(in(1));
         }
 
-        // Do we have ((x * (phi cons)) * con) ?
-        // Do we have ((x * (phi cons)) * (phi cons)) ?
-        // Push constant up through the phi: x * (phi con0*con0 con1*con1...)
+        // Do we have ((phi cons) cmp con) ?
+        // Do we have ((phi cons) cmp (phi cons)) ?
+        // Push the compare up through the phi: (phi con0 cmp con, con1 cmp con...)
         Node phicon = AddNode.phiCon(this,this instanceof EQ);
         if( phicon!=null ) return phicon;