All 2-argument boolean functions
Function(t,t)(t,f)(f,t)(f,f)
all true tttt
∨ tttf
⇐ ttft
π1ttff
⇒ tftt
π2tftf
≡ tfft
∧ tfff
¬∧ fttt
≠ fttf
¬π2ftft
¬⇒ ftff
¬π1fftt
¬⇐ fftf
¬∨ ffft
all false ffff