Prec not working

src/grammar.y

@@ -177,20 +177,20 @@ rec_op :
 
 expression:
           constant
-        | SUB_OR_NEG expression %prec UMINUS
-        | NOT expression
-        | expression ADD expression
-        | expression SUB_OR_NEG expression
-        | expression MUL expression
-        | expression DIV expression
-        | expression REM expression
-        | expression AND expression
-        | expression OR expression
-        | expression LESS_THAN expression
-        | expression EQUAL_TO expression
-        | assignable
-        | L_PAREN expression R_PAREN
-        | memOp assignable
+        | SUB_OR_NEG expression %prec UMINUS{printf("==\n");}
+        | NOT expression{printf("==\n");}
+        | expression ADD expression %prec ADD {printf("doing addition\n");}
+        | expression SUB_OR_NEG expression %prec SUB_OR_NEG{printf("subtraction\n");}
+        | expression MUL expression %prec MUL {printf("multiplication\n");}
+        | expression DIV expression %prec DIV{printf("division\n");}
+        | expression REM expression %prec REM {printf("remainder\n");}
+        | expression AND expression %prec AND {printf("and\n");}
+        | expression OR expression %prec OR {printf("or\n");}
+        | expression LESS_THAN expression %prec LESS_THAN {printf("less than\n");}
+        | expression EQUAL_TO expression %prec EQUAL_TO{printf("==\n");}
+        | assignable {printf("==\n");}
+        | L_PAREN expression R_PAREN {printf("==\n");}
+        | memOp assignable{printf("==\n");}
         ;
 
 ablock: