fact: Variables (c h l : pos n) (Hch : c <> h) (Hcl : c <> l) (Hhl : h <> l).
imports: List Arith Lia Bool Undecidability.Shared.Libs.DLW(utils list_bool pos vec subcode sss) Undecidability.StackMachines.BSM(tiles_solvable bsm_defs)