problems with the conditional operator

The if() function and the if construct don't always work symbolically. The step function 'Phi()' may be a symbolic alternative:

Success!
Luc

Incidentally, those simple theta's at the end of many of your if-blocks do not actually do something.

It's the final theta, at the end of the program that produces the result.

If you want your program to produce the result of the first if statement that is TRUE, you can use:

return theta

Where return is the programming construct, from the programming panel...

Success!
Luc