Grammatica formale per le espressioni di operazioni binarie.
Alphabet: all English words, rather than letters.
Repaceables: the structural components in an English sentence, such as <sentence>, <subject>, <predicate>, <noun>, <verb>, <article>, and so on.
Start symbol: <sentence>.
Some typical productions are:
| <sentence> → <subject> → <predicate> → <noun> → <noun> → <verb> → <article> → |
<subject><predicate> <noun> <verb><article><noun> mary algorithm wrote an |
<sentence> → <subject><predicate> models the fact that a sentence can
consist of a subject phrase and a predicate phrase.
<noun> → mary and <noun> → algorithm
mean that both "mary" and "algorithm" are possible nouns.
This approach to grammar, stemming from Chomsky's work, has influenced even elementary-school teaching.