Phc.ok_head: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/argon2/phc.bend as Phc
Lines 23-24 of bend-collections-laws-crypto@1.0.0.0/proofs/crypto/argon2/phc.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/argon2/phc.bend&start_line=23&end_line=24

import Base
import bend-collections-laws-crypto@1.0.0.0/proofs/lib/logic.bend as L

def ok_head(+x: U32, +r: List<&2, U32>, +h: {ok(x <> r) == True{} : Bool}) -> {Nat.is_lt(U32.to_nat(x), 256n) == True{} : Bool}:
  L.and_left(Nat.is_lt(U32.to_nat(x), 256n), ok(r), h)

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  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=Base/base.bend&name=U32.to_nat
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/argon2/phc.bend&name=ok
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/lib/logic.bend&name=and_left