System(playStation2) ∧ CameraAccessoryFor(playStationEyeToy, playStation2)
System(playStation3) ∧ CameraAccessoryFor(playStationEye, playStation3)  
System(playStation4) ∧ System(playStation5) ∧ CameraAccessoryFor(playStationCamera, playStation4) ∧ CameraAccessoryFor(playStationCamera, playStation5)
∀x ∀y (CameraAccessoryFor(x, y) ∧ System(y) → CompatibleWith(x, y))
¬(playStation2=playStation3) ∧ ¬(playStation2=playStation4) ∧ ¬(playStation2=playStation5) ∧ ¬(playStation3=playStation4) ∧ ¬(playStation3=playStation5) ∧ ¬(playStation4=playStation5)
∀x ∃y ∃z (System(y) ∧ System(z) ∧ ¬(y=z) ∧ CompatibleWith(x, y) ∧ CompatibleWith(x, z) → x=playstationCamera)
Compatible(playStationCamera, playStation2) ∧ Compatible(playStationCamera, playStation3) ∧ Compatible(playStationCamera, playStation4) ∧ Compatible(playStationCamera, playStation5)