Hi.

I defined the following functions:

I try to find a way to tell maple to use a specific value (e.g. zero), if the function is not real i.e. not defined, or complex etc.

Actually I want to find out, where a specific function is not defined, or has no real value. Is that possible with Maple?
Anyway, if there is no way to find out, where a specific function has no real value, I want to apply a specific real value to any value of the function, which is not real.

For example I tried the following:

How do I get a closed-form expression?

I tried the following (e.g.):

> k[21] := t-> piecewise(t<0,0,p*(1-p)^t);                      {definition of descrete probability distribution, here: geometric distribution}

I defined five functions f[i] and three functions u[j].

Afterwards I integrated f[1]*u[1] for x=-infinity..infinity and defined it as E[11].

Then I defined an equation eqn[11] := E[11] = u[1]

Last but not least I solved eqn[11] to x. So far my doing was none of a problem and produced the expected result.

Then I wanted to let maple do this procedure with all combinations of f[i] and u[j].

So I wrote the following nested for loops: