Bugs in tex-mcond

I have a different patch for tex-mcond.
I pasted the output into a TeX document and
generated a PDF (attached) from it.

FWIW

Robert Dodier

PS. Here are some example outputs:

(%i2) tex (if x < 0 then foo);

\begin{equation}
\left\{\begin{array}{ll}{\it foo} & \mathrm{if}\; x<
 0 \\ \mathbf{false}& \mathrm{otherwise}\end{array}\right.
\end{equation}

(%o2)                                false
(%i3) tex (if x < 0 then foo else bar);

\begin{equation}
\left\{\begin{array}{ll}{\it foo} & \mathrm{if}\; x<
 0 \\ {\it bar}& \mathrm{otherwise}\end{array}\right.
\end{equation}

(%o3)                                false
(%i4) tex (if x < 0 then foo elseif x > 0 then bar else baz);

\begin{equation}
\left\{\begin{array}{ll}{\it foo} & \mathrm{if}\; x<
 0 \\ {\it bar} & \mathrm{if}\; x>0 \\ {\it baz}& \mathrm{otherwise}
 \end{array}\right.
\end{equation}

(%o4)                                false
(%i5) tex (if x < 0 then foo else if x > 0 then bar else baz);

\begin{equation}
\left\{\begin{array}{ll}{\it foo} & \mathrm{if}\; x<
 0 \\ \left(\left\{\begin{array}{ll}{\it bar} & \mathrm{if}\; x>0 \\
 {\it baz}& \mathrm{otherwise}\end{array}\right.\right)
 & \mathrm{otherwise}\end{array}\right.
\end{equation}


PPS. Here's the patch.

--- src/mactex.lisp	22 Nov 2009 04:53:36 -0000	1.71
+++ src/mactex.lisp	14 Nov 2010 08:00:51 -0000
@@ -888,6 +892,11 @@
 (defprop mcond tex-mcond tex)
 (defprop %mcond tex-mcond tex)

+(setf (get 'mcond 'tex-environment)
+      `(,(format nil "~%\\begin{equation}~%") . ,(format nil
"~%\\end{equation}~%")))
+
+(setf (get '%mcond 'tex-environment) (get 'mcond 'tex-environment))
+
 (defprop %derivative tex-derivative tex)
 (defun tex-derivative (x l r)
   (tex (if $derivabbrev
@@ -939,12 +948,17 @@

 (defun tex-mcond (x l r)
   (append l
-	  (tex (cadr x) '("\\mathbf{if}\\;")
-	       '("\\;\\mathbf{then}\\;") 'mparen 'mparen)
-	  (if (eql (fifth x) '$false)
-	      (tex (caddr x) nil r 'mcond rop)
-	      (append (tex (caddr x) nil nil 'mparen 'mparen)
-		      (tex (fifth x) '("\\;\\mathbf{else}\\;") r 'mcond rop)))))
+          '("\\left\\{\\begin{array}{ll}")
+          (apply #'append
+                 (mapcar
+                   #'(lambda (p e)
+                       (if (eq p t)
+                         (tex e nil '("& \\mathrm{otherwise}") nil nil)
+                         (tex-list (list e p) nil '(" \\\\ ") " &
\\mathrm{if}\\; ")))
+                   (odds (rest x) 1)
+                   (odds (rest x) 0)))
+          '("\\end{array}\\right.")
+          r))

 (defprop mdo tex-mdo tex)
 (defprop mdoin tex-mdoin tex)
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