diff --git a/yatex.el b/yatex.el
index 966ccf4..6133d31 100644
--- a/yatex.el
+++ b/yatex.el
@@ -1,6 +1,6 @@
 ;;; yatex.el --- Yet Another tex-mode for emacs //�쒹// -*- coding: sjis -*-
 ;;; (c)1991-2017 by HIROSE Yuuji.[yuuji@yatex.org]
-;;; Last modified Thu Jan  5 23:13:56 2017 on firestorm
+;;; Last modified Tue Jan 17 22:33:39 2017 on firestorm
 ;;; $Id$
 ;;; The latest version of this software is always available at;
 ;;; http://www.yatex.org/
@@ -338,12 +338,21 @@
     ("split") ("split*") ("aligned") ("aligned*") ("alignedat") ("gathered")
     ("smallmatrix") ("cases") ("subequations")))
 ;; Prepare list(not alist) for YaTeX::ref in yatexadd.el
+(defvar YaTeX-math-other-env-alist-default
+  '(("numcases" "subnumcases"))
+  "Default alist of additional environments for equations")
+(defvar YaTeX-math-other-env-alist-private nil
+  "*User defined alist of additional environments for equations")
+(defvar YaTeX-math-other-env-alist
+  (append YaTeX-math-other-env-alist-default
+	  YaTeX-math-other-env-alist-private)
+  "Alist of additional environments for equations")
+
 (defvar YaTeX-math-begin-list
   (mapcar 'car YaTeX-ams-math-begin-alist))
 (defvar YaTeX-math-gathering-list	;used in yatexadd.el#yatex::ref
   (mapcar 'car YaTeX-ams-math-gathering-alist))
 
-
 (defvar YaTeX-ams-env-table
   (append YaTeX-ams-math-begin-alist YaTeX-ams-math-gathering-alist)
   "*Standard AMS-LaTeX(2e) environment completion table.")
@@ -370,7 +379,8 @@
 	 ("alltt")			;defined in alltt
 	 ("multicols")			;defined in multicol
 	 ("breakbox")))			;defined in eclbkbox
-   (if YaTeX-use-AMS-LaTeX YaTeX-ams-env-table))
+   (if YaTeX-use-AMS-LaTeX YaTeX-ams-env-table)
+   YaTeX-math-other-env-alist)
   "Default completion table for begin-type completion.")
 
 (defvar user-env-table nil)
diff --git a/yatexmth.el b/yatexmth.el
index ca72eb0..7f45be9 100644
--- a/yatexmth.el
+++ b/yatexmth.el
@@ -1,7 +1,7 @@
 ;;; yatexmth.el --- YaTeX math-mode-specific functions -*- coding: sjis -*-
 ;;; 
 ;;; (c)1993-2017 by HIROSE Yuuji [yuuji@yatex.org]
-;;; Last modified Thu Jan  5 17:46:22 2017 on firestorm
+;;; Last modified Tue Jan 17 22:33:52 2017 on firestorm
 ;;; $Id$
 
 ;;; Commentary:
@@ -522,7 +522,8 @@
 	      ;;  "equation*" "cases" "flalign" "flalign*"
 	      ;;  "alignat*" "xalignat" "xalignat*" "xxalignat" "xxalignat*"
 	      YaTeX-math-begin-list
-	    )))
+	    )
+	  YaTeX-math-other-env-alist))
 	(let*((p (point)) (nest 0) me0 r firstp dollar
 	      (delim (concat YaTeX-sectioning-regexp "\\|^$\\|^\C-l"))
 	      (boundary
diff --git a/yatexpkg.el b/yatexpkg.el
index 5ecc987..a2681d0 100644
--- a/yatexpkg.el
+++ b/yatexpkg.el
@@ -1,7 +1,7 @@
 ;;; yatexpkg.el --- YaTeX package manager -*- coding: sjis -*-
 ;;; 
 ;;; (c)2003-2017 by HIROSE, Yuuji [yuuji@yatex.org]
-;;; Last modified Thu Jan  5 17:46:30 2017 on firestorm
+;;; Last modified Tue Jan 17 17:42:47 2017 on firestorm
 ;;; $Id$
 
 ;;; Code:
@@ -52,6 +52,7 @@
     ("labelcpageref"	(same-as . "cref"))
     ("wrapfig"	(env "wrapfigure" "wraptable"))
     ("setspace"	(env "spacing") (section "setstretch"))
+    ("cases"	(env "numcases" "subnumcases"))
     )
   "Default package vs. macro list.
 Alists contains '(PACKAGENAME . MACROLIST)