Oasis does not correctly treat non integrating variables as constants

[TreeSnowFence]

Oasis as of right now cannot handle integrating an expression with more than one variable, if you try to do so, it will give the incorrect result.

Example to illustrate

in(2x^y, x)
expected -> (2x^(y+1))/(y+1)
actual -> in(2x^y, x)

as of right now, it basically just throws back the integral to the user instead of actually evaluating it.

[matthew-mccall]

I have confirmed this issue with the CLI

[matthew-mccall]

Also, worth noting that something like in(2/y,x) $\int \frac{2}{y} dx$ does not work either