Addresses: acme's ; is tested and documented

/a/;/b/ searches b from the end of a (acme's addr.c:170-171 sets ar to the
left side), and /a/,/b/ searches both from the current address; the review
asked that it be confirmed, and it held.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/docs/fs.md b/docs/fs.md
index d0c371c7..f98a1ae0 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -313,7 +313,9 @@ the whole text instead, its `.` kept to one line. An expression is
 evaluated from the current address, the range last written to `addr` (or
 left by the last `data` write, just past it), as acme evaluates it from
 `w->addr` (xfid.c:446): `.` is that address, not the selection (`dot` is
-the selection's own file), and `#9/re/` searches from `#9`. `/re/` searches
+the selection's own file), and `#9/re/` searches from `#9`; in `/a/;/b/`
+the second search starts at the end of the first, as acme's `;` does, where
+`/a/,/b/` starts both at the current address. `/re/` searches
 forward from the end of the current range to `limit` if one is set, and
 otherwise wraps to the start of the text; `?re?` and `-/re/` find the last
 match ending before the range, wrapping to the text's last. The match is the leftmost, but of