Num.cong_mul: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/num.bend as Num
Lines 22-23 of bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/num.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/curve25519/num.bend&start_line=22&end_line=23

import Base

def cong_mul(+a: Nat, +b: Nat, +c: Nat, +d: Nat, +e1: {a == b : Nat}, +e2: {c == d : Nat}) -> {Nat.mul(a, c) == Nat.mul(b, d) : Nat}:
  Equal.trans(Nat, Nat.mul(a, c), Nat.mul(b, c), Nat.mul(b, d), Equal.cong(Nat, Nat, t => Nat.mul(t, c), a, b, e1), Equal.cong(Nat, Nat, t => Nat.mul(b, t), c, d, e2))

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.cong
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.trans
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.mul