i, j:. (i <z j ~ ff)  ((i < j)) 

latex

ProofTree

Definitions	t  T, x:A. B(x), P  Q, P  Q, P & Q, T, P  Q, False, A, True, , A  B
Lemmas	int sq, bfalse wf, assert of le int, bnot of lt int, true wf, squash wf, eqff to assert, iff transitivity, bnot wf, le wf, le int wf, assert wf, bool wf