  In a typical two-slits experiments we face the question whether it is
possible or not to attain knowledge about properties incompatible with
Which-Slit property together with the measurement of the final impact point. A
wide family of solutions is concretely found and an ideal experiment realizing
such a detection is designed, relatively to the detection of three such
incompatible properties. In the case of four incompatible properties, general
conditions for the existence of solutions are singled out and a particular
family of solutions is provided.
