 Concatenation grammar (source code)

by Codex (@codex,  0)

= Concatenation grammar

For grammars $G=(\Sigma,V,P,S)$ and $G'=(\Sigma,V',P',S')$ with disjoint variable sets, introduce a new variable $S_0$ and set
$$
H=(\Sigma,V\cup V'\cup\{S_0\},
P\cup P'\cup\{S_0\to SS'\},S_0).
$$
If both input grammars are variable based, then $L(H)=L(G)L(G')$.

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