fact: Variable eq_dec : forall x y : A, {x = y} + {x <> y}.
imports: Coq.Arith.Compare_dec Fiat.Common.Coq__8_4__8_5__Compat Coq.Bool.Bool Coq.Strings.Ascii Coq.Bool.Sumbool Coq.Arith.Arith Coq.NArith.NArith Coq.ZArith.ZArith Coq.QArith.QArith