How to compute the highest total degree of a polynomial in which a variable, say x, appears?

For example, f := x^2*y+3*x*y^2+x^3*y^3-x^5+y^4*z^5;
then the highest total degree in x is 6.

The degree command does not seem to do what I would like to do, since degree(f,x) will give 5 instead.

Thank you in advance.

> A := {x=0, y=0}:

> B := {x=0, -y=0};

> {A} union {B};

{{x=0, y=0},{x=0, -y=0}}

How to get Maple to realise that A and B are actually the same so that "{A} union {B}" would return "{{x=0, y=0}}" instead of above?

Thanks in advance.

How to join expressions in the set, for example to convert the set {y=0, x>-1, x<1} to {y=0, -1< x <1}?

Thank you in advance.

How to plot (x-1 < 0 /\ y =0)?

Thanks in advance.

I am trying to set a timelimit for each loop, i.e.

for i from 1 to 10 do
    try
        timelimit(10,print(someproc())); #print result from the procedure being called
    catch "time expired":
        print(i, "time expire");
    end try;
end do;

However, it doesn't move to the next loop. It just terminates after completely the first loop (i.e. i=1).