[ ~ ] not, it is not the case that, it is false that
[ •, & ] and, yet, but, however, moreover, nevertheless, still, also, although, both, additionally, furthermore
[ v ] or, unless
[ ⊃ ] if…then, only if, implies, given that, in case, provided that, on condition that, sufficient condition for, necessary condition for (Not: Do not confuse antecedent with consequent!)
[ ≡ ] if and only if, is equivalent to, sufficient and necessary condition for