fact: Definition ax_HF3_false := ∀ t_f false $0 ≢ t_dum → $0 ≢ t_dum.
imports: Lia Arith Undecidability.PCP.PCP Undecidability.PCP.Util.PCP_facts Undecidability.Synthetic.DecidabilityFacts Undecidability(FOL.Utils.FullSyntax) Undecidability(FOL.FSAT) Undecidability.Shared.ListAutomation