fact: Definition steps' n x : option mm2_state := Nat.iter n (obind step') (Some x).
imports: List PeanoNat Lia Relation_Operators Operators_Properties Transitive_Closure Undecidability.MinskyMachines.MM2 Undecidability.MinskyMachines.Util.MM2_facts ssreflect ssrbool ssrfun