$\forall$${\it the\_w}$:World, $e$:E, $t$:$\mathbb{N}$.
\\[0ex]FairFifo
\\[0ex]$\Rightarrow$ isrcv(kind($e$))
\\[0ex]$\Rightarrow$ match(lnk(kind($e$));$t$;time($e$))
\\[0ex]$\Rightarrow$ (msg(a(loc($e$);time($e$))) $\in$ onlnk(lnk(kind($e$));m(source(lnk(kind($e$)));$t$)))