[ealloc]

He want more than compile-time simplification. He wants runtime simplification depending on the values encountered at runtime. For example in the quadratic equation.

And, he clearly isn't marketing it as a replacement for floating point. He says: "It is important to note, however, that the goal of the project is to make tools for symbolic calculations, not to create a viable alternative to the floating point." and he talks a lot about estimating numerical error and precision.

[stiff]

He says this about SymPy...

[ealloc]

oops you're right. Nevertheless, he clearly intends to extend rather than replace floating point since one of the goals is to estimate the errors in the floating point calculations, and he rounds.