Regular vs Context Free Grammars

Question

I\'m studying for my computing languages test, and there\'s one idea I\'m having problems wrapping my head around.

I understood that regular grammars<

Answer 1

The difference between regular and context free grammar: (N, Σ, P, S) : terminals, nonterminals, productions, starting state Terminal symbols

● elementary symbols of the language defined by a formal grammar

● abc

Nonterminal symbols (or syntactic variables)

● replaced by groups of terminal symbols according to the production rules

● ABC

regular grammar: right or left regular grammar right regular grammar, all rules obey the forms

1. B → a where B is a nonterminal in N and a is a terminal in Σ
2. B → aC where B and C are in N and a is in Σ
3. B → ε where B is in N and ε denotes the empty string, i.e. the string of length 0

left regular grammar, all rules obey the forms

1. A → a where A is a nonterminal in N and a is a terminal in Σ
2. A → Ba where A and B are in N and a is in Σ
3. A → ε where A is in N and ε is the empty string

context free grammar (CFG)

○ formal grammar in which every production rule is of the form V → w

○ V is a single nonterminal symbol

○ w is a string of terminals and/or nonterminals (w can be empty)