[Longshu] theoretical exercise (2)

Incorrect. Please note that!

3.3.3: test the number of strings with N length.

3.3.5: Write the formal definitions of the following languages

(1) lowercase strings containing all five vowels.

Nonvowel → [B-DF-HJ-NP-TV-Z]

L → (nonvowel | A) * a (nonvowel | E) * E (nonvowel | I) * I (nonvowel | O) * O (nonvowel | u) * unonvowel *

(2) lowercase string of all letters in ascending order

A * B * C *... y * z *

(3) comment, that is, the string between/* and */, and the string does not contain */that is not in double quotation marks */

Nonquote → Σ -{"}

Quote → "nonquote *"

Star → \*

Nonstarquote Σ -{",\*}

Nonstarslashquote → Σ -{",/,\*}

Comm → quote | nonstarquote | star + (nonstarslashquote | quote)

L →/starcomm * star +/

3. Grammar G: S → ASB | BSA | ABS | bas | SAB | SBA | ε

1) prove that grammar G is a binary Grammar

Evidence: The following two different syntax analysis trees can be provided for AB:

Therefore, this document serves as an example.

(2) What is the language for grammar g recognition?

It is a string of equal numbers of A and B defined on the letter {a, B.

(3) rewrite grammar g to non-Ambiguity grammar G', so that l (G) = L (G ') (too difficult, not required)

S → ABS | bas | ε

A → Baa |

B → ABB | B

[Longshu] theoretical exercise (2)