emacs-29 e521669fb3f: Fix wording in ELisp Intro manual

[Eli Zaretskii]

branch: emacs-29
commit e521669fb3f5fea6f7b9ee88cbcbcf2750c00f9d
Author: Richard Stallman <rms@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix wording in ELisp Intro manual
    
    * doc/lispintro/emacs-lisp-intro.texi (Lisp macro): Improve
    wording in description of 'unless'.  (Bug#67185)
---
 doc/lispintro/emacs-lisp-intro.texi | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/doc/lispintro/emacs-lisp-intro.texi 
b/doc/lispintro/emacs-lisp-intro.texi
index c5b33ac5eaa..e4a0f585f69 100644
--- a/doc/lispintro/emacs-lisp-intro.texi
+++ b/doc/lispintro/emacs-lisp-intro.texi
@@ -8165,9 +8165,9 @@ the expectation that all goes well has a @code{when}.  
The code uses
 text that exists.
 
 A @code{when} expression is simply a programmers' convenience.  It is
-an @code{if} without the possibility of an else clause.  In your mind,
-you can replace @code{when} with @code{if} and understand what goes
-on.  That is what the Lisp interpreter does.
+like an @code{if} without the possibility of an else clause.  In your
+mind, you can replace @code{when} with @code{if} and understand what
+goes on.  That is what the Lisp interpreter does.
 
 Technically speaking, @code{when} is a Lisp macro.  A Lisp macro
 enables you to define new control constructs and other language
@@ -8176,8 +8176,9 @@ expression which will in turn compute the value.  In this 
case, the
 other expression is an @code{if} expression.
 
 The @code{kill-region} function definition also has an @code{unless}
-macro; it is the converse of @code{when}.  The @code{unless} macro is
-an @code{if} without a then clause
+macro; it is the opposite of @code{when}.  The @code{unless} macro is
+like an @code{if} except that it has no then-clause, and it supplies
+an implicit @code{nil} for that.
 
 For more about Lisp macros, see @ref{Macros, , Macros, elisp, The GNU
 Emacs Lisp Reference Manual}.  The C programming language also