The process e+e− → ll qq at LEP and NLC

The cross sections for the reaction e+e− → ll qq and for similar four fermion production processes at LEP 1, LEP 2 and the NLC are calculated. Due to the extraordinary symmetry properties of the process, very compact analytical formulae describe the double differential distributions in the invariant masses of the ll and qq pairs. The total cross sections may be obtained with two numerical integrations.