$p_1\in +$

$p_1\in -$

$p_1\in ○$

$p_2\in +$

${\lambda }_{++}$

${\lambda }_{-+}$

${\lambda }_{○+}$

$p_2\in -$

${\lambda }_{+-}$

${\lambda }_{--}$

${\lambda }_{○-}$

$p_2\in ○$

${\lambda }_{+○}$

${\lambda }_{-○}$

${\lambda }_{○○}$