[Bruno Marchal] But how do you relate that with you experience? You have not yet told me what is the duality in the nested structured duality. You need to try to explain this without using the terms “nested”, nor “duality”. You seem not trying to explain.
[rf] Try this. Think of 'duality' as a pointer to 'quanta' or 'multiple states', and consider that such quantum features are and must be inserted first in the foundationation of mathematics (even in arithmetic), rather than as a somewhat magical add-on after a classical, non-quantum, introductory prepi-cycle. In my first pass through this terrain back in 1975-1982 -- in the Bad Old Days, back in the Reagan eras, I was imagining building a tetrahedron using four rod magnets. With my wife's metal-working help I soldered a center connector together and then played around with the five states of the inner magnetic tetrahedron. Tetra- implies poly- and inner implies outer, so in a couple of moves on the gameboard I was considering the states of all inner and outer "bipolar polyhedral structures" (bps). So, if you follow, I upgraded the term from 'bipolar' to 'duality'. Originally, though, I came around to noticing that even forgetting about magnets and just making a structure out of anything, to my way of thinking there would always be a tiny, maybe what mathematicians might call "infinitesimal difference" between one end (half) of a radii or edge. One half could have a few more electrons or photons or quanta on one half than the other, So the ends are different, similar to what is overtly present with magnets, but now more subtle, tending to the point of practically indistinguishable.
That's the original meaning/origin of "duality" as in "nested structured~duality", to me. That's why I sometimes qualify it a "difference", and it could be a difference or duality in many different traits of features.
In the last few weeks, I have remembered that I used to think that ALL structures, even the highly idealized ones, are ~actually 'bipolar polyhedral structures' existing or having multiple states. That is, that there are not the two categories: {regular, bipolar}, but just the one category: {bipolar}.