A normal form theorem for label grammars
β Scribed by Matthias Jantzen; Manfred Opp
- Publisher
- Springer
- Year
- 1981
- Tongue
- English
- Weight
- 956 KB
- Volume
- 14
- Category
- Article
- ISSN
- 1433-0490
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
Productions of a context-free grammar can be given coefficients from semirings, inducing weights for both derivations in the grammar and strings over the terminal alphabet. For a weighted context-free grammar in Greibach normal form, the weight of any string, as well as the set of derivations of the
We prove a local normal form theorem of the Gaifman type for the infinitary logic LβΟ(Q u ) Ο whose formulas involve arbitrary unary quantifiers but finite quantifier rank. We use a local Ehrenfeucht-FraΓ―ssΓ© type game similar to the one in [9]. A consequence is that every sentence of LβΟ(Q u ) Ο of
A XORMAL FORM THEOREM FOR RECURSIVE OPERATORS Lemma 2. All elements of 9 ? and the element I are perfect. If E and rj are perfect elements of 9, then (t, q ) is also perfect. Proof. Obvious from the definition. L e m m a 3. Let [ be a perfect element of 9. Then Vp(L(p7, [) = 9 & R ( [ . y ) = 9).