Solving a nonlinear system with equations with non-negative variables

Hi all,

I have a system of nonlinear equations with for equations, 4 variables I want to solve for, and 2 parameters. All of the variables and parameters must be non-negative.

The code I used to try to do this is:

Where eq_i (i = 1, ... , 4) are expression (not equations in themselves). For example, eq₁ is:

When I try to run this code I get the following error:

"Error, (in SolveTools:-Inequality:-Piecewise) piecewise takes at least 2 parameters"

Can anyone help me how I can make Maple do what I want here? :)

Thank you in advance,

JTamas