Maxima error when having strings in terms



Hello,

the following nasty behaviour of Maxima we encountered
when applying Maxima to statistical problems, where
strings naturally show up:

Maxima 5.20.1 http://maxima.sourceforge.net
using Lisp ECL 9.12.3
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) is("x">0);
Maxima encountered a Lisp error:
 "x" is not of type LIST.
(%i2) is(f("x")>0);
Maxima encountered a Lisp error:
 "x" is not of type LIST.
(%i3) declare(f, posfun);
(%i4) is(f(1) > 0);
(%o4) true
(%i5) is(f("x") > 0);
Maxima encountered a Lisp error:
 "x" is not of type LIST.

This seems like a clear bug to me, and hopefully something can be done
(otherwise our statistics application seem to become very clumsy, always
having to translate strings into, say, numbers).

Oliver

-- 
Dr. Oliver Kullmann
Computer Science Department
Swansea University
Faraday Building, Singleton Park
Swansea SA2 8PP, UK
http://cs.swan.ac.uk/~csoliver/