Goal:
    x : t  X : lt x x
  ============================
   False


DEBUG:Going to execute:
try intros until H; intro_block H;
            (try simpl in H; DepElim.simplify_equations_in H);
            DepElim.generalize_by_eqs_vars H; CoreTactics.block_goal; 
            tac H; CoreTactics.intros_until_block