SemiLinearSets 

See the definition for linear and semilinear sets in the following: [[attachment:SemiLinearSets.pdf]]

The old tex file is attached here: [[attachment:SemiLinearSets.tex]]


'''Definition (Linear Set)''' Let $$N$$ be the set of nonnegative integers and $$k$$ be a positive integer. A set $$S\subseteq N^{k}$$ is a ''linear set'' if $$\exists v_{0},v_{1},...,v_{t}$$ in $$N^{k}$$ such that

$$S=\left\{ v~|~v=v_{0}+a_{1}v_{1}+...+a_{t}v_{t},a_{i}\in N\right\}$$$

The vector $$v_{0}$$ (referred to as the ''constant vector'') and $$v_{1},v_{2},...,v_{t}$$ (referred to as the ''periods'') are called the ''generators'' of the linear set $$S$$.

'''Definition (Semilinear Set)''' A set $$S\subseteq N^{k}$$ is ''semilinear'' if it is a finite union of linear sets. $$\emptyset$$ is a trivial semilinear set where the set of generators is empty. ''Every finite subset of '' $$N^{k}$$ ''is semilinear'' - it is a finite union of linear sets whose generators are constant vectors. Clearly, ''semilinear'' sets are closed under union and projection. It is also know that semilinear sets are closed under
intersection and complementation.

The definition are from: [http://www.eecs.wsu.edu/~zdang/papers/catalytic.pdf Catalytic P Systems, Semilinear Sets, and Vector Addition Systems]