## Cardinality of (*a*,*b*) Pair Densities in Abstract Predecessor Tree

### -- based on same "power-of-2" depths (less lopsided)

-- based on many more, less dense (but still infinite) subsets

-- use the density contribution of every (*a,b*) pair in
2^{a}*3^{b} coefficients

-- in general there are several paths to any
2^{a}*3^{b}**n*+{*c*}
formula, because *e(s|b)*_{(m-1)}t will have all
permuations of *s-*steps and *b-*steps

-- when sorted the file of formulas of the abstract tree nodes reveals the
cardinalities of the sets sharing an (*a,b*) pair

-- the cardinalities are the elements of the Fibonacci series

-- the situation is easily envisaged using
Pascal's triangle

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