Question: How to write a function of three variables with two discrete ones and a continuous one?

I am trying to write a program for the representation of a function F with three variables i, j, x, where i, j are non-negative integers and x is real. I have tried with different indexings like F(i,j,x), F[i](j,x), F[i,j](x), but did not get the desired result. My objective is to get F as a function of i, j, x.

Here is my maple code with detailed description of my problems in each step.

Please Wait...