(* needed to implement Stdlib.Numbers.NatInt.NZBitsSpec *)
Definition shiftl_spec_high a n m (_:0<=m) := shiftl_specif_high a n m.(* needed to implement Stdlib.Numbers.NatInt.NZBitsSpec *)
Definition shiftr_spec a n m (_:0<=m) := shiftr_specif a n m.

Lemma tail_add_spec n m : tail_add n m = n + m.