1 files changed, 8 insertions, 2 deletions
diff --git a/chapter13/docs/13-grammar.md b/chapter13/docs/13-grammar.md
index 65611618..63871a39 100644
--- a/chapter13/docs/13-grammar.md
+++ b/chapter13/docs/13-grammar.md
@@ -20,8 +20,14 @@ statement
     | metaStatement
     ;
 
+PRIMTYPE
+    : 'int'
+    | 'flt'
+    ;
+
 field
-    : 'int' IDENTIFIER ';'
+    : PRIMTYPE IDENTIFIER ';'
+    | structName IDENTIFIER ('?')? ';'
     ;
 
 fields
@@ -66,7 +72,7 @@ structName
     ;
 
 declStatement
-    : 'int' IDENTIFIER '=' expression ';'
+    : PRIMTYPE IDENTIFIER '=' expression ';'
     | structName IDENTIFIER ('?')? '=' expression ';'
     ;