x_ is a pattern which matches to any expression. I wanted to be able to
have something like
f : a(b(c),d) -> d(c) for all c,d and fixed a,b
As you see, it's not just about substituting, but about extracting also.
--
Andrei Zorine
Stavros Macrakis wrote:
>>in fact I want to have something like mathematica's x_
>>pattern to use it inside some bigger expression.
>
>
> I am not familiar with Mathematica semantics. What exactly is a
> Mathematica x_ pattern, and how does it work?
>
> Maybe we would understand better how to help you solve your problem if
> you would give us more background. What exactly are you trying to do?
>
> -s
>
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>