fact: Fixpoint prod_decode_snd (p : positive) : option positive := match p with | p~0~0 => (~0) <$> prod_decode_snd p | p~0~1 => (~0) <$> prod_decode_snd p | p~1~0 => Some match prod_decode_snd p with Some q => q~1 | _ => 1 end | p~1~1 => Some match prod_decode_snd p with Some q => q~1 | _ => 1 end | 1~0 => Some 1 | 1~1 => Some 1 | 1 => None end.
imports: Coq.QArith(QArith_base Qcanon) stdpp(well_founded) stdpp(options)