ProofShift.drop_set0: law of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/proof_shift.bend as ProofShift
Lines 52-58 of lawful-bytes@0.1.1.0/proof_shift.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/proof_shift.bend&start_line=52&end_line=58

import Base

# Setting the first element of drop(xs, j).
law drop_set0:
  for +xs: List<&2, U32>
  for +j: Nat
  for +x: U32
  for +h: {Nat.is_lt(j, List.length(&2, U32, xs)) == True{} : Bool}
  {List.set(&2, U32, List.drop(&2, U32, xs, j), 0n, x) == x <> List.drop(&2, U32, xs, Nat.add(j, 1n)) : List<&2, U32>}

Uses (13):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Empty.absurd
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.drop
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.set
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=lawful-arrays@0.1.0.0/proof_base.bend&name=lt_zero_absurd
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/proof_append.bend&name=drop_zero