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The open logic and its relation to circumscription
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作者 林作铨 李未 《Science China(Technological Sciences)》 SCIE EI CAS 1999年第1期44-53,共10页
The open logic is defined by model theory which can be viewed as a process-based nonmonotonic logic. Some new notions and results of open logic are introduced. The relation of open logic to circumscription is studied,... The open logic is defined by model theory which can be viewed as a process-based nonmonotonic logic. Some new notions and results of open logic are introduced. The relation of open logic to circumscription is studied, and the relationship between open logic and other nonmonotonic logics is pointed out as well. 展开更多
关键词 OPEN LOGIC nonmonotonic LOGIC circumscription.
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Chemosystematics Studies on Six Varieties of <i>Mangifera indica</i>L.
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作者 Celestine Uzoma Aguoru Christopher Ogbodo Joseph Olalekan Olasan 《Agricultural Sciences》 2017年第3期253-259,共7页
Taxonomic investigation was carried out on six (6) varieties of Mangifera indica (Julie, Broken, Peter, Kerosene, Opioro and Big fibre) using chemosystematics evidence. Extracts obtained from the leaf of each variety ... Taxonomic investigation was carried out on six (6) varieties of Mangifera indica (Julie, Broken, Peter, Kerosene, Opioro and Big fibre) using chemosystematics evidence. Extracts obtained from the leaf of each variety were phyto-chemically screened and quantified. Gravimetric and spectroscopic approaches were adopted in the quantification of active principles common to all the six varieties. Binary matrices computed from qualitative assessment were analysed to yield a dendrogram using the Average Linkage Method. Quantitative values were subjected to appropriate descriptive and inferential statistical analysis. All varieties possessed alkaloid except Big-fibre. Peter and Kerosene varieties lacked saponin, an active principle present in other varieties. Anthraquinone was present in all except in Julie and Opioro. Five out of the six varieties lacked phlobatannin. All varieties had tannin, steroid, flavonoid and reducing sugar. Tannin was lowest in Big-fibre (0.43%) but highest in Opioro (2.41%). Steroid ranged from 3.8% in Opioro to 9.0% in Julie with a standard deviation of 1.84. Julie variety recording the lowest composition in flavonoid (0.01%) and reducing sugar (0.04%) components was notable. Comparison of the mean values of phytochemicals has shown a statistically significant difference (p = 0.0005) with a large F-value (18.244). Using the LSD mean separation, steroid was the most remarkable phytochemical contributing to the significant differences. Dendrogram revealed very close relationship between Julie and Opioro varieties. The remaining four were divergent and distinct although Broken and Peter varieties arose from the same ancestral lineage with Julie and Opioro. However, Big-fibre and Kerosene varieties were clearly different from rest belonging to a different phylogenetic ancestor. With these remarkable differences, they ought to be given special taxonomic and systematic review for appropriate nomenclatural assignment. The six varieties of Mangifera indica investigated are thus clearly partitioned and therefore recommended to be circumscribed. This approach is maiden, and considered innovative as it is employed in this study for the first time in the taxonomy of Mangifera. 展开更多
关键词 Chemosystematics MANGIFERA INDICA VARIETIES Phytochemicals Taxonomy circumscription
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Tableau Systems for Paraconsistency and Minimal Inconsistency 被引量:1
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作者 林作铨 sxx0.math.pku.edu.cn 《Journal of Computer Science & Technology》 SCIE EI CSCD 1998年第2期174-188,共15页
In this paper, the sematics of a paraconsistent logic and its nonmonotonic extension by minimal inconsistency are presented first. And then signed tableaux for paraconsistelit logic and minimal tableaux for logic of... In this paper, the sematics of a paraconsistent logic and its nonmonotonic extension by minimal inconsistency are presented first. And then signed tableaux for paraconsistelit logic and minimal tableaux for logic of minimal inconsistency is proposetl. Finally the reduction of logic of paraconsistency and minimal inconsistency on ordinary semantics which provides new approach to proof procedure and implementation of paraconsistency and minimal inconsistency are provided. 展开更多
关键词 Tableaux logic of paradox paraconsistent logic minimal inconsistency nonmonotonic logic circumscription
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