Fuzzy logic (Zadeh, Kosko, etc) developed up to its more simple version of it: YinYang Fuzzy Bipolar Equilibirum (Zhang).
The problem that fuzzy logic overcomes is that the so called «Formal» logic is trying to be «The parent logic of all logics» by meaning that any dualism is necessarily adversarial (truth or false) while it can’t prove it (i.e. this phrase is false). So since we can’t find the issolated 1 and we need it to be in a relation, a relation of 2 is the minimum unit we can reasonable approach. And more exactly speaking, the more accurate unity is the outcome of a retrograde relation between 2 (i.e. niyan).
Dual should simply mean that there are 2 parts (of a united constant) in a whole. Dual doesn’t and shouldn’t mean that the relation is rival-adversarial or each one of the 2 are static or absolute, just because in essence they are always relative and so are just different (maybe opposed-antagonist) poles. This is why some people use Bipolar instead of Dual, for meaning that Bipolar is not Rival, but we should risk in bringing back the reminder of: «Dual can be antangonist, but not even that is necessarily adversarial».
Within any duality, we will always find aesthetics that will help us to differentiate the properties of each of the two polarities. Since dualities are scalar and grown out from the same essential simplifiable mechanism (integrally superpositioned), aesthetics differentiate the poles always in the same basic way.. I.e. when a dualism gets complexer, one pair will still be Yin (Femenine) and the other Yang (masculine), same for the seconds and the thirds of a triad.
So «dual fuzzyness» or «dual constant» are the better terms to use when we talk about the relation within a duality, or the most simplified form of «Fuzzyness, the parent of all logics, and or the more complementary Yin pair of the Formal logic Yang». Even fuzzy itself should consider sets of 2 and 3 as its core.
Duality seems realer when it is interpreted as a fuzzy constant
See more: Theory