{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

September 14 - CSCI 2670 Introduction to Theory of...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
CSCI 2670 Introduction to Theory of Computing September 14, 2005
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Agenda • Yesterday – Pumping lemma • Today – Introduce context-free grammars – Formally define CFG’s – Begin designing CFG’s • Tomorrow – More on designing CFG’s – Chomsky normal form
Image of page 2
Announcement Quiz tomorrow – Regular expressions – Pumping lemma
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Context-free grammars The shortcoming of finite automata is that each state has very limited meaning – You have no memory of where you’ve been – only knowledge of where you are Context-free grammars are a more powerful method of describing languages – Example: {0 n 1 n | n 0} is a CFG
Image of page 4