Christopher Smith

We must be careful with operations involving relationals. Most importantly, we cannot divide by any factor unless it is known to be positive or negative. And the notion of adding...

> For fully recursive solution, we necessarily need to recurse back to `apply`, Thanks for pointing that out. (I had been experimenting with modifying `bottom_up` and this was a carry-over...

``` 1162 has been committed. ``` Original comment: http://code.google.com/p/sympy/issues/detail?id=3172#c3 Original author: https://code.google.com/u/117933771799683895267/

This looks good to me. Can you test it locally?

Regarding conversion to Rational unconditionally, see comment [here](https://github.com/sympy/sympy/issues/21162#issuecomment-2005005728).

I'm not sure how needed this is since `expr.subs(*eq.args)` or `expr.subs(*solve(linear, sym, dict=True)` both work, where `eq` is an Equality and `linear` is an equation that is linear in `sym`.

> Wait, can you target entire _expressions_ for replacement in `subs`? If so Yes - but it only works if the expression is an exact leaf in the expression true...

I'm +0, too. Solutions to equations can already be obtained as a dictionary. And we don't allow multiple dictionaries so `(x+y).subs([{x:1},{y:2}])` does not work. But that sort of thing is...

> Especially for something as trivial as this that should quite frankly already be a feature I'll ask for feedback on the mailing list. > Relational.swap ```pthon >>> Eq(x,y).reversed Eq(y,...

> But again, Equality.args just isn't mentioned in the documentation One could use `(eq.lhs, eq.rhs)` if `args` is not known. Accepting other containers (today Eq, tomorrow Matrix or TableForm) violates...