Question: Maple command to find domain of function where it is real valued

Does Maple have a function which finds the domain of its variables such that the function is real valued?

I am only interested in a function of two variables, x and y.  I'd like to know what is the range of x and y, where f(x,y) is real valued.

For example, given f(x,y)= x * ln(y), then the domain is all of x, and for y>0.    So it is the upper half plane.  For f(x,y)=sin(x)*cos(y), then it is the whole plane (all x and all y) and so on. 

I looked at singular(), and this does part of what I want, but it only gives me the singular points. So for the above it gives y=0 and x=x, but I am looking for something a little more specific. I also looked at package called RealDomain, but I do not see how to use this for what I want to do. But I could have missed something.

I do not know what the function is beforehand, but it will always be a function of x and y, and I need an automated way to determine the range of x and y where this function is real valued. 

I can't do plots and look at them, since this is all automated and has to be done algorithmically only and non-interactive.

I could use singular, and try evaluating the function at different points and see if it produces real or complex values, but this is not practial to do and can fail.

Does Maple have support for such functionality?