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Unformatted text preview: Problem 5. Unrestricted grammars , UG, are generalizations of Context Free Grammars, where the left hand side is not restricted to being a single nonterminal symbol anymore. Each rule of an UG is a nonempty string of variables and/or terminals on the left and any string of variables and/or terminals on the right. Formally, the production rules of an UG are dened as R ( V ) + ( V ) * . For example, AbC b is a valid rule in some UG. It is known that UGs generate exactly all languages that can be recognized by a Turing Machine. In this problem, you are asked to give an UG for the language { a n b n c n  n } . 1...
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This note was uploaded on 04/29/2010 for the course ECS 222 taught by Professor Mr. during the Spring '10 term at UC Davis.
 Spring '10
 mr.

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