From aa06c9405451e1ca611ab94e279bb27bb9786cfe Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Mon, 16 Sep 2024 10:41:28 -0700
Subject: [PATCH] math/big: add clarifying (internal) comment

Follow-up on CL 467555.

Change-Id: I1815b5def656ae4b86c31385ad0737f0465fa2d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/613535
Auto-Submit: Robert Griesemer <gri@google.com>
TryBot-Bypass: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Tim King <taking@google.com>
---
 src/math/big/natdiv.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/math/big/natdiv.go b/src/math/big/natdiv.go
index 084ac72658..2e66e3425c 100644
--- a/src/math/big/natdiv.go
+++ b/src/math/big/natdiv.go
@@ -643,6 +643,7 @@ func (q nat) divBasic(u, v nat) {
 	rec := reciprocalWord(vn1)
 
 	// Invent a leading 0 for u, for the first iteration.
+	// Invariant: ujn == u[j+n] in each iteration.
 	ujn := Word(0)
 
 	// Compute each digit of quotient.
-- 
2.48.1