One problematic example is one in which the budget set is not a function in all sections. For example a budget set that is broken in three sections: from x=0 to 4, the budget is defined as y=8. From x > 4 to x < 10 y = -0.5x + 10 and finaly x = 10 for y < 5.
Perhaps part of my problem is my inability to specify an implicit piecewise expression. Following the same example (and supposing the function where not a simple line, but a more complex function) and not withstanding the non-function segment, if the budget set where defined explicitly like
I can plot it without any problem, but if it is defined implicilty like
plotting won't work. The problem goes beyond plotting since that could be done with line segments, what I would like to do is be able to work with more complex examples and operate on them as I would with any normal funciton.