$\forall$$u$, $v$, $w$:$\mathbb{B}$. ($\uparrow$($u$ $\Rightarrow_{b}$ $v$)) $\Rightarrow$ ($\uparrow$($v$ $\Rightarrow_{b}$ $w$)) $\Rightarrow$ ($\uparrow$($u$ $\Rightarrow_{b}$ $w$))