🏗 Formal generative grammar

=== a fully explicit 📖 Formal grammar==

Formal definition

• $N$: finite set of non-terminal symbols
• $\sum$: finite set of terminal symbols disjoint from $NL$
• $S$: start symbol, $\in$ $N$
• $P$: finite set of rules of type $\alpha \to \beta$
  • $\alpha ,\beta \in (N\bigcup \sum )$
  • $\alpha$ conaining min 1 non-terminal symbol