A novel graph-theoretical identity for the sextet polynomial

1982 ◽  
Vol 89 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Sherif El-Basil
2018 ◽  
Vol 13 (2) ◽  
pp. 23-42
Author(s):  
Márta Ujvári

In this paper I show that a novel ontic reading of explanation, intending to capture the de re essential features of individuals, can support the qualitative view of individual essences. It is argued further that the putative harmful consequences of the Leibniz Principle (PII) and its converse for the qualitative view can be avoided, provided that individual essences are not construed in the style of the naïve bundle theory with set-theoretical identity- conditions. Adopting either the more sophisticated two-tier BT or, alternatively, the neo-Aristotelian position of taking essences as natures in the Aristotelian sense, can help to evade these main charges against the qualitative view. The functional parallels with the alternative haecceitistic view of individuation and individual essence will also be considered.


1984 ◽  
Vol 39 (3) ◽  
pp. 276-281
Author(s):  
Ivan Gutman ◽  
Sherif El-Basil

AbstractA graph-theoretical method for the calculation of the sextet polynomial is proposed. The method is easy and generally applicable. It is based on the construction of the Clar graph and on the calculation of its independence numbers.


1982 ◽  
Vol 37 (1) ◽  
pp. 69-73
Author(s):  
Ivan Gutman

Abstract A number of mathematical relations for the sextet polynomial are derived. A graph has been introduced (the so called C-graph), representing those properties of a benzenoid system which are essential in the sextet theory of Clar. The main structural properties of the C-graph are deter-mined. The obtained results contribute towards a better understanding of the algebraic and combinatorial background of Clar's theory of the aromatic sextet.


1970 ◽  
Vol 8 (1) ◽  
pp. 25-36 ◽  
Author(s):  
John Kekes
Keyword(s):  

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