(Required environment): Update required emacsen.

diff --git a/README.en b/README.en
index ef841a8..be3e414 100644 (file)
--- a/README.en
+++ b/README.en
@@ -34,11 +34,14 @@ What's SEMI?
 Required environment
 ====================
 
-  SEMI supports XEmacs 20.2 or later with mule, and Emacs 20.
+  SEMI supports XEmacs 21.1 or later, and GNU Emacs 20.4 or later.
 
-  SEMI does not support anything older than Emacs 19.28 or XEmacs
-  19.14.  SEMI also does not support Emacs 19.29 to 19.34, XEmacs
-  19.15 or XEmacs 20.2 without mule, but SEMI may work with them.
+  SEMI does not support anything older than GNU Emacs 19.28 or XEmacs
+  19.14.  In addition, SEMI does not word with byte-indexing Mule
+  implementations, such as Mule 1, Mule 2 and GNU Emacs 20.1/20.2.
+
+  SEMI also does not support Emacs 19.29 to 19.34, XEmacs 19.15 or
+  XEmacs 20.2, but SEMI may work with them.
 
   SEMI requires APEL (9.22 or later) and FLIM (1.14.1 or later)
   package.  Please install them before installing it.  APEL package is