Goal:
    x : t  X : lt x x
  ============================
   (let H := CoreTactics.block in let H0 := CoreTactics.block in False)


DEBUG:Going to execute:
fun id cont =>
             DepElim.generalize_sig_gen id
              ltac:(fun id id' id'1 t =>
                      move_after_deps id' t; CoreTactics.revert_until id';
                       rename id' into id; cont id'1 id)