law shift_view_t

lawful-bytes@0.1.1.0 · proof_shift.bend:460

import Base
import lawful-bytes@0.1.1.0/defs.bend as D
import lawful-bytes@0.1.1.0/bytes.bend as B
import lawful-bytes@0.1.1.0/proof_core.bend as C
import lawful-arrays@0.1.0.0/proof_tree.bend as P

460law shift_view_t:
461  for +len: U32
462  for +t: P.Tree<U32>
463  for +d: Nat
464  for +k: U32
465  for +h: {D.ok(C.BT(len, t), d) == True{} : Bool}
466  for +hk: {Nat.is_le(U32.to_nat(k), D.size(C.BT(len, t))) == True{} : Bool}
467  {D.view(B.shift(C.BT(len, t), k)) == List.drop(&2, U32, D.view(C.BT(len, t)), U32.to_nat(k)) : List<&2, U32>}