law idx_add
import lawful-words@0.1.0.0/proof_bytes.bend as ProofBytesimport Base
454law idx_add:
455 for +j: Nat
456 for +s: Nat
457 for +k: Nat
458 {Nat.add(Nat.add(Nat.mul(8n, j), k), Nat.mul(8n, s)) == Nat.add(Nat.mul(8n, Nat.add(j, s)), k) : Nat}