+ if (to_zap) {
+#ifdef DEBUG_SYMBOL_TREE
+ LOG(astring("zapping node for ") + to_zap->name());
+#endif
+ int found = which(to_zap); // find the node in the tree.
+ if (negative(found)) return common::NOT_FOUND; // not found.
+#ifdef DEBUG_SYMBOL_TREE
+ int kids = _associations->symbols();
+#endif
+ _associations->whack(to_zap->name()); // remove from associations.