-#define E_OR(dep1, dep2) (((dep1)>(dep2))?(dep1):(dep2))
-#define E_AND(dep1, dep2) (((dep1)<(dep2))?(dep1):(dep2))
-#define E_NOT(dep) (2-(dep))
+#define EXPR_OR(dep1, dep2) (((dep1)>(dep2))?(dep1):(dep2))
+#define EXPR_AND(dep1, dep2) (((dep1)<(dep2))?(dep1):(dep2))
+#define EXPR_NOT(dep) (2-(dep))
+
+#define expr_list_for_each_sym(l, e, s) \
+ for (e = (l); e && (s = e->right.sym); e = e->left.expr)