fact: Variable P : list (mm_instr (pos 2)).
imports: List Arith Lia Relations Undecidability.MinskyMachines(MMA mma_defs ndMM2) Undecidability.Shared.Libs.DLW(utils Vec.pos Vec.vec Code.subcode Code.sss) Undecidability.Synthetic(Definitions ReducibilityFacts)