Properties of Boolean functions/hard
| Studies of Boolean functions |
| Properties of Boolean functions | |
|---|---|
| hard | soft |
| binary | binary |
| integer | integer |
| permutation | permutation |
Hard properties can be assigned to a BF, without referencing its arity.
weight
Weight is the quotient of true and all places of the truth table. It is usually shown as an integer for a given arity (soft weight).
This triangle shows the numbers of BF by weight.
nonlinearity
Nonlinearity is the extent to which a BF is not linear. It is usually shown as an integer for a given arity (soft nonlinearity).
atoms
Atoms or atomvals are the relevant arguments of the BF. They correspond to the circles of an Euler diagram. The number of atoms is the valency.
I this project the letters A, B, C... correspond to atoms 0, 1, 2... E.g. has atoms 1 and 2.
root
The root of a BF created by replacing its atoms with the set {0, ..., valency−1}.
When it is its own root, the BF is dense.
equivalence classes
based on input negation and permutation: family (negation), faction (permutation), clan (both) (Typically represented by Smallest Zhegalkin index.)
extended by complement: super-family, super-faction, super-clan (Families and clans can be self-complementary. Factions can not.)
(Further extension by half-complement leads to ultra-famlies and -clans, which are soft properties.)
prefect
The prefect is a way to assign each BF to a linear BF. A linear is assigned to itself. (3-ary images)
| calculating prefect from Zhegalkin index | |||
|---|---|---|---|
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The possible results are the linear functions. | |||
These properties assign every almost every BF to a finite set of integers. The result for the contradiction is infinite. Soft equivalents have been defined to avoid this problem.
The cardinalities of the results are gravity and depth.
_to_prefect_5.svg.png)
_to_prefect_~6.svg.png)
_to_prefect_~7.svg.png)


