Final answer:
The statement is false, since regular languages are a subset of context-free languages; to show a language is not regular, one must typically use the pumping lemma for regular languages.
Step-by-step explanation:
To answer the question, false, showing that a language is context-free does not automatically mean that it is not regular. In formal language theory, all regular languages are by definition also context-free, as the class of regular languages is a strict subset of the class of context-free languages. However, the reverse is not true; not all context-free languages are regular. Therefore, to demonstrate that a language is not regular, one typically uses the pumping lemma for regular languages, which provides a method for showing that a language cannot be represented by a regular expression or finite automaton.
To prove that a language L is not regular, one cannot directly show that it is context-free. A language can be non-regular but not context-free. In fact, the set of context-free languages is a proper superset of the set of regular languages.
To show that a language is not regular, one can use the Pumping Lemma for Regular Languages. This lemma provides a way to prove that a language does not fulfill the requirements for regularity. If the pumping lemma cannot be applied to a language L, then L cannot be regular.