Aczel non-well founded set theory which allows sets that contains themselves, together with intuitionistic logic, as a starting point.
Propositions as embeddings in hilbert spaces (infinite dimensional spaces). Propositions can only "interact" with other proposition along non-zero dimensions that they have in common. Universes as collections of propositions. (Here propositions could be both mathematical concepts, and complex things like the position in spacetime of somehing) Multiverse as the space containing all universes. Note that universes are themselves of the same type as propositions here. The Multiverse in my construction is an infinitely self-recursive structure, that contain within itself all possible propositions. Universes can merge, if they are commensurable (shared dimensions in hilbert space). Universes "annihilate" when there are contradictions, and create by branching new universes when a truth value cannot be established by known propositions. You could call propositions, particles or being if you prefer another point of view . At this stage, we only deal with symbols not meaning.
In fact, I started toying with assigning labels to propositions and came up with a scheme based on prime numbers and p-adic numbers (where I posed 0-adic numbers to be prime numbers). It just seemed to work better.
In addition, I had a "creation" operator that would introduce a new dimension (when reaching infinity, or transcendence... a sort of koopman operator to access divine wisdom via samadhi... remember I wanted to express all possibilities, including the existence and truthfullness or lack there-off of all concepts in religions). The whole system was based on a construction similar to surreal numbers, but using infinites instead of finite numbers, and adding dimensions at each turn.
0 = {|} 1 = {|0} -Infinity = {0,{0}|} Infinity = {|{0},0}