Goal:
  
  ============================
   (forall x y : t, true = eqb x y -> x = y)


DEBUG:Going to execute:
simpl; intros; Tactics.destruct_all_rec_calls;
            repeat (Tactics.destruct_conjs; simpl proj1_sig in *); subst *;
            Tactics.autoinjections; try Tactics.discriminates;
            try (solve
             [ red; intros; Tactics.destruct_conjs; Tactics.autoinjections;
                Tactics.discriminates ])