def FV
import lawful-fields@0.1.1.0/proof_cut.bend as ProofCutimport 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
634def FV(+len: U32, +t: P.Tree<U32>, +s: U32, +to: U32, +sep: U32) -> U32:
635 Pair.snd(D.Bytes, U32, B.find(C.BT(len, t), s, to, sep))