Hello Aaron, On Wed, Mar 13, 2013 at 1:42 AM, Aaron Meurer <[email protected]> wrote: > There's no consistency here. Aside from the two issues you mentioned, > there's also https://code.google.com/p/sympy/issues/detail?id=2571. > So Lambda, Subs, and Integral are three classes that use bound > variables, and each treats them slightly differently. We need to > figure out which treatment makes the most sense and use it everywhere.
It looks to me that there won't be a consensus, because these different semantics matter and can make life harder depending on what you want to do (see the problem with substituting variables in Integrals for instance). What I think we should do is to separate use cases and create new functions (or options) with clearly defined meanings. I vaguely remember that Chris did (or started) something like that once, but I didn't follow it at the time. Using PR #1888 as an example, i had to change a `expr.has(x)` to `x in expr.free_symbols` because the change in the internal implementation of Subs (using dummies or not) changes the semantic of has(). Renato -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
