What is the additional rule that characterizes an essentially noncontracting grammar?
Understand the Problem
The question is asking about a specific rule in the context of formal grammar theory, particularly about a rule that characterizes an essentially noncontracting grammar.
Answer
C) S → ε
The final answer is C) S → ε
Answer for screen readers
The final answer is C) S → ε
More Information
In an essentially noncontracting grammar, there is an additional rule that disallows the start symbol S from deriving the empty string ε. This ensures that the grammar generates only non-empty strings.
Tips
Common mistake: Confusing essentially noncontracting grammars with noncontracting grammars. Noncontracting grammars do not have this additional rule.
Sources
- Formal Languages and Automata Theory - geeksforgeeks.org
- Essentially Non-Contracting Grammars - en.wikipedia.org