$\forall$${\it the\_w}$:World, $e$:E.
\\[0ex]FairFifo $\Rightarrow$ ($\uparrow$isrcv(kind($e$))) $\Rightarrow$ ($\exists$$t$:\{0..time($e$)$^{-}$\}. ($\uparrow$match(lnk(kind($e$));$t$;time($e$))))