T-55, T-72 and T-90 battle are USSR/Russian origin battle tanks and are respectively based on first, second and third generation battle tank technologies.
If 'P 3 Q' means 'P is daughter of Q', 'P 5 Q' means 'P is father of Q', 'P 7 Q' means 'P is mother of Q' and 'P 9 Q' means 'P is sister of Q', then how is J related to K in J 3 L 9 N 3 O 5 K?