fact: Fixpoint findCollision_1 (A B : Set)(eqda : EqDec A)(eqdb : EqDec B)(ls : list (A * B))(a : A)(b : B) := match ls with | nil => None | (a', b') :: ls' => if (eqb b b' && (negb (eqb a a'))) then (Some a') else (findCollision_1 _ _ ls' a b) end.
imports: FCF PRF SplitVector cAU CompFold DetSem SemEquiv