∀ {a b : Lean.Expr} {ea eb : Lean.Grind.AC.Expr} {a_1 b_1 : Lean.Expr} {ea_1 eb_1 : Lean.Grind.AC.Expr},
  Lean.Meta.Grind.AC.EqCnstrProof.core a b ea eb = Lean.Meta.Grind.AC.EqCnstrProof.core a_1 b_1 ea_1 eb_1 →
    a = a_1 ∧ b = b_1 ∧ ea = ea_1 ∧ eb = eb_1