# Problems regarding one formula:

Question asked by stefan.kleinschuster@keora.at on Aug 7, 2014
Latest reply on Aug 8, 2014 by oliverbastert@fico.com

Hi Everybody!

I'm fairly new to Xpress and had to develop an ILP for my thesis and calculate it with Xpress.

Now I am stuck on a formula I don't know how to express within the Mosel language. Maybe you guys can help me.

It's about assigning referees to the right matches within a soccer season

the formula:

1/Tr (forall m in M) ∑ d(r,m) + x(r,m) - 1/T^r (forall m in M) ∑ d(^r,m) + x(^r,m) <= dmax        for all r, ^r in R

Tr is a target value and is given

d(r,m) is the distance between referee r and match m

dmax is the maximum difference each referee is allowed to have to each other

x(r,m) is the wanted variable if referee r is assigned to match m or not

M and R are just the sets - 180 Matches, 10 Referees (Austria, small country )

I don't know how to compare each referee with each other referee within the Mosel system...

any ideas?