# The book says 27 terminals but I only see 10. Where are they?

On page 103 of Mike Sisper's Introdution to Theory of Computation, it says that the grammar has 27 terminals (26 being the letters of the English Alphabet and 1 being the space character) but in the rules above, I don't see those 27 terminals. I only see 10 which are "a", "the", "boy", "girl", "flower", "touches", "likes", "sees", and "with". So my question is, what does the book mean? Is this an error?

• They counted every letter a-z plus a space character. It is explaind in parentheses right after the "27 terminals", so the word "with" for instance consist is a word of 4 terminals w, i, t, h. Apr 8 at 20:17
• @ttnick How does one determine what terminals a CFG has from looking at its rules? Apr 9 at 5:38
• @ttnick "In parentheses" is one claim. The rule list shows ten non-variables, giving rise to Sbeve's question. I'd call it an inconsistency, or lack of completeness if those ten are neither variables nor terminals. Apr 9 at 6:45

$$G_2$$ is however just a toy example spanning a small fragment of the English language, in which case $$\Sigma_1$$ = {a, the, boy, girl, flower, touches, likes, sees, with, ␣} would be as fine as $$\Sigma_2$$ = {a, b, $$\ldots$$ , z, ␣} if not more.