Uniform probability distribution function.
Uniform(g,a,b)
Generates a random variate following the Uniform probability distribution function in the interval [a,b].
The pseudo-code algorithm used for this distribution is:
1. Generate u as U(0,1)
2. Return x = a + (b-a)*u
(u,g) := Uniform(g,2,4);
function Uniform extends Var; end Uniform;