Is There A Simple,Pedestrian Arithmetic Sentence Which Is Independent Of Zfc?

We show that the P < NP conjecture can beformulated as a Pi₂ ⁰ sentence, and explore some of theconsequences of that fact. This paper summarizes recent workby the author with N. C. A. da Costa on the P相似文献   

Varieties of Three-Valued Heyting Algebras with a Quantifier

This paper is devoted to the study of some subvarieties of the variety Qof Q-Heyting algebras, that is, Heyting algebras with a quantifier. In particular, a deeper investigation is carried out in the variety Q ₃ of three-valued Q-Heyting algebras to show that the structure of the lattice of subvarieties of Qis far more complicated that the lattice of subvarieties of Heyting algebras. We determine the simple and subdirectly irreducible algebras in Q ₃ and we construct the lattice of subvarieties (Q ₃ ) of the variety Q ₃ .     

On the symmetric treatment of an asymmetric approach to factor analysis

On the assumption that a partitioning can be found such that three mutually exclusive test vector configurations span the same factor space, a procedure is derived whereby symmetric parts of the correlation matrix are estimated from functions of asymmetric parts treated symmetrically. This yields an explicit matrix formula for communality estimation which generalizes earlier work by Albert. Conventional factoring methods, with all their computational and fitting advantages, can be applied once the symmetric portions of the correlation matrix have been estimated. Extension to four subgroups of test vectors allows for a matrix generalization of the old tetrad difference criterion to the multiple-factor case.     

Subverting Culture: Promoting HIV/AIDS Prevention Among Puerto Rican and Dominican Women

This article discusses the challenges faced by researchers and interventionists when attempting to promote change in social norms and normative beliefs that promote HIV/AIDS risk-related behaviors among Puerto Rican and Dominican women. The article focuses on the role of culture in HIV/AIDS prevention with women by analyzing the sociohistorical context of some cultural beliefs and by illustrating the tension between risk-related and protective cultural beliefs in research conducted by the authors with women in both New York and Puerto Rico. The authors propose that promoting changes in sex-related social norms and normative beliefs might be constructed as a subversive act and present the challenge this analysis poses for community psychology. They conclude that this conceptualization might be construed as subversive because rather than idealizing culture, it promotes changes that respect diversity within the culture and foster participation in the development of new cultural values, beliefs and norms.     

Distinguishing Serial and Parallel Parsing

This paper discusses ways of determining whether the human parser is serial maintaining at most, one structural interpretation at each parse state, or whether it is parallel, maintaining more than one structural interpretation in at least some circumstances. We make four points. The first two counterclaims made by Lewis (2000): (1) that the availability of alternative structures should not vary as a function of the disambiguating material in some ranked parallel models; and (2) that parallel models predict a slow down during the ambiguous region for more syntactically ambiguous structures. Our other points concern potential methods for seeking experimental evidence relevant to the serial/parallel question. We discuss effects of the plausibility of a secondary structure in the ambiguous region (Pearlmutter & Mendelsohn, 1999) and suggest examining the distribution of reaction times in the disambiguating region.     

Stroop interference and negative priming: Problems with inferences from null results

The Stroop color-naming effect has often been taken as evidence for the automaticity of word processing (MacLeod, 1991). Recently, Besner, Stolz, and Boutilier (1997) reported that coloring a single letter instead of the whole word eliminated the Stroop effect. From this finding, they concluded that word processing could not be purely automatic, since it can be prevented. We asked whether the elimination of the Stroop effect is sufficient evidence for concluding that the word is not processed. Combining Besner et al.’s manipulation with a negative-priming procedure, we found intact negative priming from the prime color word in the absence of a Stroop effect. This result clearly indicates that the meaning of the prime word was processed. The findings highlight the importance of using converging methods to evaluate lack of processing.