Slide 1Courtesy Costas Busch - RPI1 Linear Bounded Automata LBAs Slide 2 Courtesy Costas Busch - RPI2 Linear Bounded Automata (LBAs) are the same as Turing Machines with…

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

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

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

Slide 1 Courtesy Costas Busch - RPI1 NPDAs Accept Context-Free Languages Slide 2 Courtesy Costas Busch - RPI2 Instantaneous Description Current state Remaining input Current…

Slide 1 Courtesy Costas Busch - RPI1 Turing’s Thesis Slide 2 Courtesy Costas Busch - RPI2 Turing’s thesis: Any computation carried out by mechanical means can be performed…

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

Slide 1 Courtesy Costas Busch - RPI1 Non-regular languages Slide 2 Courtesy Costas Busch - RPI2 Regular languages Non-regular languages Slide 3 Courtesy Costas Busch - RPI3…

Slide 1 Courtesy Costas Busch - RPI1 Reducibility Slide 2 Courtesy Costas Busch - RPI2 Problem is reduced to problem If we can solve problem then we can solve problem Slide…

Pushdown Automata PDAs Courtesy Costas Busch - RPI Pushdown Automaton -- PDA Input String Stack States Courtesy Costas Busch - RPI Initial Stack Symbol Stack Stack bottom…