avl-tree-stack-pop
avl-tree-stack-pop is a compiled Lisp function in `avl-tree.el
'.
(avl-tree-stack-pop AVL-TREE-STACK &optional NILFLAG)
Pop the first element from AVL-TREE-STACK.
(See also `avl-tree-stack').
Returns nil if the stack is empty, or NILFLAG if specified.
(The latter allows an empty stack to be distinguished from
a null element stored in the AVL tree.)