Improve documentation of 'seq-difference'

* doc/lispref/sequences.texi (Sequence Functions):
* lisp/emacs-lisp/seq.el (seq-difference): Clarify the documentation of
'seq-difference'.  (Bug#80257)

2 files changed, 6 insertions, 5 deletions

diff --git a/doc/lispref/sequences.texi b/doc/lispref/sequences.texi
index 853b577c910..afee255346c 100644
--- a/doc/lispref/sequences.texi
+++ b/doc/lispref/sequences.texi
@@ -1125,10 +1125,11 @@ two arguments to use to compare elements instead of the default
 
 
 @defun seq-difference sequence1 sequence2 &optional function
-  This function returns a list of the elements that appear in
-@var{sequence1} but not in @var{sequence2}.  If the optional argument
-@var{function} is non-@code{nil}, it is a function of two arguments to
-use to compare elements instead of the default @code{equal}.
+  This function returns a copy of @var{sequence1} from which the
+elements that appear in @var{sequence2} were removed.  If the optional
+argument @var{function} is non-@code{nil}, it is a function of two
+arguments to use to compare elements instead of the default
+@code{equal}.
 
 @example
 @group
diff --git a/lisp/emacs-lisp/seq.el b/lisp/emacs-lisp/seq.el
index 881fae951b6..e0a41b380b5 100644
--- a/lisp/emacs-lisp/seq.el
+++ b/lisp/emacs-lisp/seq.el
@@ -579,7 +579,7 @@ This does not modify SEQUENCE1 or SEQUENCE2."
               '()))
 
 (cl-defgeneric seq-difference (sequence1 sequence2 &optional testfn)
-  "Return list of all the elements that appear in SEQUENCE1 but not in SEQUENCE2.
+  "Return copy of SEQUENCE1 with elements that appear in SEQUENCE2 removed.
 \"Equality\" of elements is defined by the function TESTFN, which
 defaults to `equal'.
 This does not modify SEQUENCE1 or SEQUENCE2."