Yuhang "Eric" Wei

I'm working on this issue and I've come up with one possible solution. We could still use the "substitute all constants Ci to one" strategy, because it is convenient to...

The main problem with a substitution-free approach here is that the return values of `default_sort_key`, which relies on `sort_key` methods of several classes, have a pattern that depends on the...

Indeed that will still fail. I guess we should do a `constantsimp` (defined in the same file) before substituting all the new constants to `1`. That would transform `1 /...

Really I failed to consider those situations, thank you for the correction. Now I've tried to rewrite the `sort_key` method for the `Expr` class. While keeping everything else basically unchanged,...

It's possible to add an optional parameter to the `Expr.sort_key` method to pass all the constant symbols. But I think the most elegant way here is to define a subclass...

I'm not sure what you mean by that, but it appears here we can't just use Dummy variables: ```python In [15]: D1 = Dummy('D1') In [16]: D2 = Dummy('D2') In...

It seems there would be much work to do to introduce this special type of symbol. Will it be okay to temporarily use this rewriting of the `Expr.sort_key` method as...

OK, I understand. I thought the usage of this symbol would be wider. Then if we are limiting the usage of this kind of symbol in sorting here, should it...

After some attempts I found that we can't just define a class of constant symbol and override the sort key method to make it return a number's sort key, like...

Honestly speaking the name `set_max_unchanged_iterations` was a bit confusing when I first looked at it, so I think it could be a good idea to rename it to something like...