ptree
static void ptree(struct op *, int, struct shf *);
ptree(va_arg(va, struct op *), indent, shf);
STACK_OF(GENERAL_SUBTREE) **ptree = NULL;
ptree = &ncons->permittedSubtrees;
ptree = &ncons->excludedSubtrees;
if (!*ptree)
*ptree = sk_GENERAL_SUBTREE_new_null();
if (!*ptree || !sk_GENERAL_SUBTREE_push(*ptree, sub))