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Properties of Boolean functions/soft/integer

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Properties of
Boolean functions
hard soft
binary binary
integer integer
permutation permutation

Soft properties depend on the arity of the BF.
Integer properties have consecutive non-negative integers as values.


softened

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weight

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the number of true places in the truth table of length 2arity   (hard weight is a fraction)

extent to which a BF is not linear   (hard nonlinearity is a fraction)

gravity and depth

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2gravity and 2depth are the cardinalities of legion and cohort. Equivalently for the softened properties. Only the result for the contradiction differs from hard gravity and depth.

consul (binary Walsh spectrum)

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twin prefect oddness

The Walsh spectrum is the product of a truth table with a Walsh matrix.
The binary Walsh spectrum is the product of a truth table with a binary Walsh matrix, using F2 operations (mod 2).
It is always a Walsh function, and shall be called consul. The term is also used for the integer denoting the Walsh function.

One could refine the consul with a sign. That signed consul would be the twin prefect.
So the (unsigned) consul is the Walsh index of the twin prefect. (See an overview for arity 3.)

The consul weight is the binary weight of the consul integer. (E.g. consul 6 has consul weight 2.)

sharp family with consuls 0...7
blunt family with consul 2
(compare 4-ary family with consul 6)
3-ary families with Walsh spectra (integers) and consuls (red backgrounds on the right)

patron

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The patron of a BF is the XOR of itself and its twin. It is a noble.    (3-ary images)

praetor

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XOR of left and right half of the truth table.    (3-ary images)

quaestor

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XOR of left and reversed right half of the truth table (i.e. of the coordinates in the Hasse matrix)    (3-ary images)

faction XOR and crest

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The XOR of all BF in a faction is a symmetric BF. It can be converted to an integer . E.g. for 3-ary BF to integers 0...15.
Often the FX of a BF is complementary to that of its complement. These BF are crested, and the BF is called crest. The crested BF are partitioned into blocks of equal size.
The FX of a BF can also be equal to that of its complement. These BF are uncrested.
faction XOR, is crested, crest, great crest, super great crest