fact: Example F3 : Formula L := forallH 0 (orH (equal (var 0) a) (existH 1 (equal (var 0) (f (var 1))))).
imports: Coq(Arith Lists.List) hydras.Ackermann(fol folProp folProof Languages folLogic folLogic2 folLogic3 subAll Deduction primRec)