fact: Example test_optimize_0plus: optimize_0plus (APlus (ANum 2) (APlus (ANum 0) (APlus (ANum 0) (ANum 1)))) = APlus (ANum 2) (ANum 1).
imports: Coq.Bool.Bool Coq.Arith.Arith Coq.Arith.EqNat Coq.omega.Omega Coq.Lists.List Coq.omega.Omega Maps