[Date Index] [Thread Index] [Author Index]

Re: FullForm puzzle.

• To: mathgroup at smc.vnet.net
• Subject: [mg106268] Re: [mg106248] FullForm puzzle.
• From: Jack L Goldberg 1 <jackgold at umich.edu>
• Date: Thu, 7 Jan 2010 02:28:01 -0500 (EST)

Fellow mathematistas:

I sent this post to the two responders but thought it might be of interest

  I use a transformations in some of my code that takes a <= x <= b  
and converts it into a function I have defined called "characteristic  
function" - the name is obviously irrelevant.  But to make this  
transformation I need to know what the FullForm is. If it (the  
FullForm) varies from one command to another, how can I count on my  
transformation working.  For example, suppose a line in my Module  
looks like this:
(1)        "something"/.LessEqual[2,x,3] -> characteristic[x,2,3]

But if "something" contains the FullForm "Inequality[ ... ]" the  
transformation explicit in (1) will fail.

I ran into this and found a simple work-around.  However, it took me a  
couple of hours to pinpoint the problem since it was imbedded in a  
relatively long code.

Jack