#include "avl.h" forall(otype T | Comparable(T)) int ?==?(T t1, T t2) { return !(t1 < t2) && !(t2 < t1); } forall(otype T | Comparable(T)) int ?>?(T t1, T t2) { return t2 < t1; } forall(dtype T | { void ^?{}(T *); }) void delete(T * x) { if (x) { ^?{}(x); free(x); } }