The regular part of a semigroup of transformations with restricted range

2011 ◽  
Vol 83 (1) ◽  
pp. 134-146 ◽  
Author(s):  
Jintana Sanwong
Mathematics ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 134
Author(s):  
Chollawat Pookpienlert ◽  
Preeyanuch Honyam ◽  
Jintana Sanwong

Let T(X,Y) be the semigroup consisting of all total transformations from X into a fixed nonempty subset Y of X. For an equivalence relation ρ on X, let ρ^ be the restriction of ρ on Y, R a cross-section of Y/ρ^ and define T(X,Y,ρ,R) to be the set of all total transformations α from X into Y such that α preserves both ρ (if (a,b)∈ρ, then (aα,bα)∈ρ) and R (if r∈R, then rα∈R). T(X,Y,ρ,R) is then a subsemigroup of T(X,Y). In this paper, we give descriptions of Green’s relations on T(X,Y,ρ,R), and these results extend the results on T(X,Y) and T(X,ρ,R) when taking ρ to be the identity relation and Y=X, respectively.


Author(s):  
Jintana Sanwong ◽  
Worachead Sommanee

LetT(X)be the full transformation semigroup on the setXand letT(X,Y)={α∈T(X):Xα⊆Y}. ThenT(X,Y)is a sub-semigroup ofT(X)determined by a nonempty subsetYofX. In this paper, we give a necessary and sufficient condition forT(X,Y)to be regular. In the case thatT(X,Y)is not regular, the largest regular sub-semigroup is obtained and this sub-semigroup is shown to determine the Green's relations onT(X,Y). Also, a class of maximal inverse sub-semigroups ofT(X,Y)is obtained.


Author(s):  
Worachead Sommanee

Let TX be the full transformation semigroup on a set X. For a fixed nonempty subset Y of a set X, let TX,Y be the semigroup consisting of all full transformations from X into Y. In a paper published in 2008, Sanwong and Sommanee proved that the set FX,Y=α∈TX,Y:Xα=Yα is the largest regular subsemigroup of TX,Y. In this paper, we describe the maximal inverse subsemigroups of FX,Y and completely determine all the maximal regular subsemigroups of its ideals.


2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.


Author(s):  
Theodore G. Van Raalte

Whereas disputations were a regular part of both elementary pedagogy and university training in the medieval and early-modern eras, not all disputations were of the same kind. This chapter explains the differences between the dialectic and scholastic disputations, of which Chandieu’s works belong to the latter. Further, it shows that Chandieu wrote his works “for the better practice of disputations,” and that his “theological and scholastic” treatises thus have an organic connection to the classroom. The use of disputations in the academies of the Swiss cantons more widely is also described. Comparisons to the structure of Thomas’s disputations occurs, as well as to that of an earlier Arabic philosopher.


2015 ◽  
Vol 44 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Vítor H. Fernandes ◽  
Preeyanuch Honyam ◽  
Teresa M. Quinteiro ◽  
Boorapa Singha
Keyword(s):  

1970 ◽  
Vol 17 (2) ◽  
pp. 121-125 ◽  
Author(s):  
C. W. McArthur

It is known (13, p. 92) that each closed normal cone in a weakly sequentially complete locally convex space is regular and fully regular. Part of the main theorem of this paper shows that a certain amount of weak sequential completeness is necessary in order that each closed normal cone be regular. Specifically, it is shown that each closed normal cone in a Fréchet space is regular if and only if each closed subspace with an unconditional basis is weakly sequentially complete. If E is a strongly separable conjugate of a Banach space it is shown that each closed normal cone in E is fully regular. If E is a Banach space with an unconditional basis it is shown that each closed normal cone in E is fully regular if and only if E is the conjugate of a Banach space.


2013 ◽  
Vol 91 (2) ◽  
pp. 301-308 ◽  
Author(s):  
José Luis Guil-Guerrero ◽  
Francisco Gómez-Mercado ◽  
Rebeca Pilar Ramos-Bueno ◽  
Miguel Ángel Rincón-Cervera ◽  
Elena Venegas-Venegas

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