Why would pairs of two be favorable?
> So for example, ternary logic is (much) more efficient than binary logic. Having that 3rd state just makes problem solving much more elegant.
What do you have in mind here?
> Like, are there all sorts of exotic logic gates that come from a 4 state system?
I don't know but you may be interested in this [1].
1. https://en.wikipedia.org/wiki/Catu%E1%B9%A3ko%E1%B9%ADi
Why would pairs of two be favorable?
> So for example, ternary logic is (much) more efficient than binary logic. Having that 3rd state just makes problem solving much more elegant.
What do you have in mind here?
> Like, are there all sorts of exotic logic gates that come from a 4 state system?
I don't know but you may be interested in this [1].
1. https://en.wikipedia.org/wiki/Catu%E1%B9%A3ko%E1%B9%ADi