Not sure what would be the best name. Is there a Math::Expression::Simple? If you were going with Light, I think personally, I find Math::Expression::Light better semantically.

I did something similar a while back. It had some non-math functions, though it didn't support multiple statements per expression. Though I might go fix that now. ;)

I started wrapping it up into a module and I too had some trouble thinking of an appropriate package, then other events caused it to get dropped by the way side, so I never did come up with what I thought was an appropriate name.