Slide 1Fall 2006Costas Busch - RPI1 A Universal Turing Machine Slide 2 Fall 2006Costas Busch - RPI2 Turing Machines are hardwired they execute only one program A limitation…

Slide 1Fall 2006Costas Busch - RPI1 Decidable Languages Slide 2 Fall 2006Costas Busch - RPI2 Recall that: A language is Turing-Acceptable if there is a Turing machine that…

Slide 1 Fall 2006Costas Busch - RPI1 Turing’s Thesis Slide 2 Fall 2006Costas Busch - RPI2 Turing’s thesis (1930): Any computation carried out by mechanical means can…

Slide 1 Costas Busch - RPI1 Pushdown Automata PDAs Slide 2 Costas Busch - RPI2 Pushdown Automaton -- PDA Input String Stack States Slide 3 Costas Busch - RPI3 Initial Stack…

Slide 1 Costas Busch - RPI1 NPDAs Accept Context-Free Languages Slide 2 Costas Busch - RPI2 Context-Free Languages (Grammars) Languages Accepted by NPDAs Theorem: Slide 3…

Slide 1 Costas Busch - RPI1 Standard Representations of Regular Languages Regular Languages DFAs NFAs Regular Expressions Regular Grammars Slide 2 Costas Busch - RPI2 When…

Slide 1 Fall 2005Costas Busch - RPI1 Recursively Enumerable and Recursive Languages Slide 2 Fall 2005Costas Busch - RPI2 Definition: A language is recursively enumerable…

Slide 1 Costas Busch - RPI1 Turing Machines Slide 2 Costas Busch - RPI2 The Language Hierarchy Regular Languages Context-Free Languages ? ? Slide 3 Costas Busch - RPI3 Regular…

Slide 1 Fall 2005Costas Busch - RPI1 Pushdown Automata PDAs Slide 2 Fall 2005Costas Busch - RPI2 Pushdown Automaton -- PDA Input String Stack States Slide 3 Fall 2005Costas…

Slide 1 Costas Busch - RPI1 More Applications of the Pumping Lemma Slide 2 Costas Busch - RPI2 The Pumping Lemma: Given a infinite regular language there exists an integer…