Plus42 algebraic expressions update

[Thomas Okken]

Yes, programs and equations will all be able to call each other. And yes, I was planning to make the order of parameters in the F(A:B:C) notation match the order in which they are shown in the CALC menu, or the order of MVARs when calling a program. I suppose an additional, position-independent syntax like F(X=1:Y=2:Z=3) is also an option, but that's a minor implementation detail, I'm not worrying about that yet.