On 2013-08-14, Richard Fateman <fateman at gmail.com> wrote:
> For a start, let me observe that the pattern matching program has
> undergone some alterations since I wrote it in 1969 or so.
Yeah -- I've fixed a lot of bugs.
> Some of these changes are noted in the source code and consist of the
> disabling of error messages. Some accompanying comments indicate
> that ... because some programmer who went into the code and did not
> understand it and did not understand the message, did not ask the author
> for clarification, decided to just strike it out.
I don't suppose you're willing to talk about specifics here.
> Secondly, the process of pattern matching generally puts the objects
> being matched into a canonical form, so that in trying to match (y-yy)^2,
> before anything happens, that expression is changed to y^2-2*y*yy+yy^2.
No, it doesn't, and it shouldn't.
Robert Dodier