fact: Definition well_founded_lift_ltb : well_founded lift_ltb.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.MSets.MSetInterface Coq.MSets.MSetFacts Coq.MSets.MSetProperties Fiat.Common.Wf Fiat.Common.LogicFacts Fiat.Common.Instances Fiat.Common.NatFacts Fiat.Common.MSetExtensions Fiat.Common