Transparent Float.of_bits.
Transparent Float32.of_bits.

Lemma pos_lor_inj:  (* not true *)
forall k N (a b: nan_pl k),
Zpower_nat 2 (Z.to_nat (k-2)) = Zpos N ->
Pos.lor (proj1_sig a) N =  Pos.lor (proj1_sig b) N ->
a=b.