law fgo2_view

lawful-bytes@0.1.1.0 · proof_find.bend:362

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

362# hit says byte j is c1 or c2, r holds byte j + 1, j + n = to.
363law fgo2_view:
364  for +n: Nat
365  for +hit: Bool
366  for +len: U32
367  for +t: P.Tree<U32>
368  for +d: Nat
369  for +j: U32
370  for +to: U32
371  for +c1: U32
372  for +c2: U32
373  for +hh: {(U32.is_eq(C.AT(len, t, j), c1) || U32.is_eq(C.AT(len, t, j), c2)) == hit : Bool}
374  for +hn: {Nat.add(U32.to_nat(j), n) == U32.to_nat(to) : Nat}
375  for +hto: {Nat.is_le(U32.to_nat(to), U32.to_nat(len)) == True{} : Bool}
376  for +h: {D.ok(C.BT(len, t), d) == True{} : Bool}
377  {U32.to_nat(Pair.snd(D.Bytes, U32, B.find2.go(n, hit, (C.BT(len, t), C.AT(len, t, (j + 1 : U32))), j, to, c1, c2))) == Nat.add(U32.to_nat(j), D.run_len2(D.slice(D.view(C.BT(len, t)), U32.to_nat(j), n), c1, c2)) : Nat}