Common.update: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/spec/lib/common.bend as Common
Lines 80-88 of bend-collections-laws-math@1.0.0.0/spec/lib/common.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/spec/lib/common.bend&start_line=80&end_line=88

import Base

# Replace element i (no change when i is out of range).
def update(-A: Data, xs: List<&2, A>, i: Nat, x: A) -> List<&2, A>:
  match xs i:
    case Nil{} _:
      Nil{}
    case Con{h, t} 0n:
      Con{x, t}
    case Con{h, t} 1n+p:
      Con{h, update(A, t, p, x)}

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat