T, X:Type, eq:EqDecider(X), f, g:x:X fp Type, x:X. f  g  f(x)?Void  g(x)?T 

latex

Definitions	False, A & B, f  g, EqDecider(T), f(x)?z, Unit, P  Q, P & Q, f(x), P  Q, x  dom(f), a:A fp B(a), Top, x. t(x), , Prop, b, A, b, x:A. B(x), t  T
Lemmas	assert wf, not wf, bnot wf, fpf-trivial-subtype-top, fpf-dom wf, fpf-ap wf, assert of bnot, eqff to assert, iff transitivity, eqtt to assert, bool wf, fpf-cap wf, deq wf, fpf wf, fpf-sub wf