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Unformatted text preview: 1. (10 marks) Write down a regular expression that describes the language of binary strings that represent numbers that are powers of two. 10 * Typical mistakes: Some people couldn’t remember which end of a binary representation was the low end (and so wrote 0 * 1). Others forgot that 2 = 1 not 0. Others confused powers of two with squares, or anything of the form a b and so created quite hard questions for themselves. 2. (15 marks) If these names stand for classes of languages: FINITE – the class of finite languages REGEXP – the class of languages described by regular expressions REGG – the class of languages generated by regular grammars DFSA - the class of languages accepted by deterministic finite state automata CFG – the class of languages generated by context free grammars show all the relationships among these classes using the symbols ⊆ for ‘is a subset of’ and ⊂ for ‘is a strict subset of’....
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This note was uploaded on 01/25/2011 for the course CSE 105 taught by Professor Mr.elienasr during the Spring '10 term at American University of Science & Tech.
- Spring '10