[Openmcl-devel] inverse function

Tim Bradshaw tfb at tfeb.org
Sun Feb 21 21:40:36 UTC 2010


On 13 Feb 2010, at 19:10, Taoufik Dachraoui wrote:

> What I would like to have is a function to generate an inverse of a  
> given lisp function
> (without side-effects) if it has an inverse and the generated  
> inverse function returns
> all possible results (as in sqrt above).

A belated note on this (I've been away): the inverse of square is not,  
in fact sqrt, since (= (sqrt (square -1))) is not true, for instance.   
This may seem a trivial point, but it demonstrates how hard this kind  
of thing is to get right even in what looks like "simple" cases.  No  
more is ASIN the inverse of SIN for instance.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.clozure.com/pipermail/openmcl-devel/attachments/20100221/05b39342/attachment.html>


More information about the Openmcl-devel mailing list