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"Defense Technical Information Center" .
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"vau" .
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"New proofs of old theorems in logic and formal linguistics."@en .
"NOV 1966" .
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"en" .
"1966" .
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"19" .
"227469361"^^ .
"Theorem 1 constructs, from any word problem in a semi-Thue system, an equivalent Post correspondence problem, showing the undecidability of the general Post correspondence problem. Theorem 2 constructs, from any Post correspondence problem, a minimal linear grammar which is ambiguous exactly if the Post correspondence problem has a solution, showing the undecidability of the general ambiguity problem. (Other standard undecidability results on phrase structure grammars are implied.) Theorem 3 constructs, from any word problem in a semi-Thue system, an ambiguity problem, combining the results of Theorem 1 and 2 by more direct means. No new results are presented, but standard proofs were shortened and constructions eliminated, combined, or simplified. (Author)."@en .
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"Theorems)"@en .
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"CARNEGIE INST OF TECH PITTSBURGH PA." .
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"Linguistics."@en .
"(Linguistics."@en .
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"Ft. Belvoir" .
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"Floyd, Robert W." .
"Floyd" .
"Robert W." .
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"Grammars."@en .
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