def internal_shift

bend-mathlib@0.8.1.0 · perm.bend:6

import Base

6def internal_shift(+s: List<&2, Nat>) -> List<&2, Nat>:
7  match s:
8    case Nil{}:
9      Nil{}
10    case +i <> rest:
11      (1n+i) <> internal_shift(rest)