fact: Definition ax_HER3 := ∀ ∀ ∀ ∀ $3 ≡ $2 → $1 ≡ $0 → f_less $3 $1 → f_less $2 $0.
imports: Lia Arith Undecidability.PCP.PCP Undecidability.PCP.Util.PCP_facts Undecidability.Synthetic.DecidabilityFacts Undecidability(FOL.Utils.FullSyntax) Undecidability(FOL.FSAT) Undecidability.Shared.ListAutomation