Feature Request: User Definable Expressions.

[MonkeyFish]

I love the user-definable functions and variables, but I'd like to take it further! I'd like a User Definable Expression please.

So if I defined r = ^-1, then 2r = 2^-1 = 0.5.

This would stack up in the same way as writing in full, so with r = ^-1 and M = e6, then 2Mr = 2e6^-1 = 0.5e-6

This would seriously shorten the number of characters I would type for frequently used expressions. I'm already setting M as a variable '1e6', so that 2M = 2e6, but then I run into trouble with 2M^-1, as it performs the reciprocal on 1e6 before it multiplies the ans with 2 (as it should with a variable). If M was recognised as just 'e6' it would work!