KK theory

In math, the KK theory is a theory where there's a fifth dimension, instead of only 4 (time, depth, width, length). It was introduced by Russian mathematician Gennadi Kasparov in 1980.

$[F,\rho (a)],(F^2-1)\rho (a),(F-F^{*})\rho (a)$ (This is the first version. Feel free to edit.)