fact: Definition shiftl a n := match norm_pos a, n with | Pos a, Pos n => Pos (NN.shiftl a n) | Pos a, Neg n => Pos (NN.shiftr a n) | Neg a, Pos n => Neg (NN.shiftl a n) | Neg a, Neg n => Neg (NN.succ (NN.shiftr (NN.pred a) n)) end.
imports: ZArith Lia BigNumPrelude NSig ZSig