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From: billw@hpcvra.cv.hp.com. (William C Wickes)
Newsgroups: comp.sys.handhelds
Subject: Re: A couple things.
Message-ID: <25590153@hpcvra.cv.hp.com.>
Date: 30 Apr 91 21:13:08 GMT
References: <1991Apr30.054632.10264@colorado.edu>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 12

When you differentiate a built-in function for which the 48 has no
derivative, it returns a function derNAME(args), where NAME is the
function name (see page 422 in the manual).  This allows you to make
your own derivative, by creating a user-defined function named
derNAME.  However, certain one-character function names, like !, can't
be used in global names unless they are preceded by the escape character
(27).  The 48 provides for this by using der<ESC><char> as the
derivative name, where <ESC> is the escape character, and <char> is the
original function name.

Bill Wickes
HP Corvallis