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  4. 1978
Showing papers in "Demonstratio Mathematica in 1978"
Journal Article•10.1515/DEMA-1978-0323•
Determining ideals of a given finite index in a finitely presented semigroup

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Andrzej Jura
01 Jul 1978-Demonstratio Mathematica

28 citations

Journal Article•10.1515/DEMA-1978-0404•
ALMOST r-CONTACT HYPERBOLIC STRUCTURE IN A PRODUCT MANIFOLD

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K. K. Dube, Ram Niwas
01 Oct 1978-Demonstratio Mathematica

7 citations

Journal Article•10.1515/DEMA-1978-0109•
Propriétés asymptotiques des solutions d'un système de deux équations différentielles linéaires homogènes du premier ordre

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Jerzy Radzikowski
01 Jan 1978-Demonstratio Mathematica
TL;DR: In this paper, the propriétés asymptotiques des solution du système (1.1) seulement dans le cas où les coefficients a = a(t), d = d(t) of the solution sont bornés for t € I; au §2 nous admettons, de plus, que for tout t e I les coefficients b = b(t, c = c(t)) sont positifs.
Abstract: Toute solution saturée de ce système est donc définie dans l'intervalle I. Dans ce travail nous étudions les propriétés asymptotiques des solution du système (1.1) seulement dans le cas où les coefficients a = a(t), d = d(t) de ce système sont bornés pour t € I; au §2 nous admettons, de plus, que pour tout t e I les coefficients b = b(t), c = c(t) sont positifs,. au §3 nous les supposons négatifs* Dans l'étude des propriétés asymptotiques du système ( 1 . 1 ) nous appliquons la méthode topologique de Vatewski [3]• Dans ce travail nous admettons les définitions posées dans [1].

7 citations

Journal Article•10.1515/DEMA-1978-0403•
A local property of the subspaces of euclidean differential spaces

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Adam Kowalczyk, Jan Kubarski
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this article, the weakest logarithm of the form C|A where or e c is defined on the form of a C is given, where C is defined as a C where or E c.
Abstract: 1 . P r e l i m i n a r e s Let M ¿ 0 be a s e t and C an a r b i t r a r y s e t of r e a l f u n c t i o n s d e f i n e d on M. We denote by r c the weakest t o p o logy on M such t h a t a l l f u n c t i o n s b e l o n g i n g t o C are c o n t i n u o u s . Por any s e t A c o n t a i n e d i n M we denote by ClA the s e t of f u n c t i o n s of the form » |A where or e C. We denote by C^ the s e t o f a l l r e a l f u n c t i o n s on A such t h a t f o r any p o i n t p of A t h e r e e x i s t s i n r c an open n e i g h bourhood U of p and a f u n c t i o n a e C, such t h a t n U = = a | A O U. I t i s easy to v e r i f y t h a t , f o r any s e t A c M, we have r c = t\"C|A = *\"C|A. I n p a r t i c u l a r r^, = r c > We denote

6 citations

Journal Article•10.1515/DEMA-1978-0123•
CONCERNING NON-REMOVABLE IDEALS IN COMMUTATIVE m-CONVEX ALGEBRAS

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Wieslaw Zelazko
01 Jan 1978-Demonstratio Mathematica
TL;DR: In this paper, the authors consider complete topological algebras, i.e., topological algebra which are complete as the topological linear spaces, and define a jointly continuous associative multiplication.
Abstract: All algebras in this paper are assumed to be commutative, unital, with the unit element denoted by e, and linear over the field C of complex numbers. A topological algebra is a topological linear space in which is defined a jointly continuous associative multiplication. We shall consider only the complete algebras, i.e. topological algebras which are complete as the topological linear spaces. By a superalgebra of a topological algebra A we mean any topological algebra B containing a subalgebra topologically isomorphic to A (which we identify with A and so write A c B) and having the same unit element as A. If K is any class of topological algebras, then ideal I of an algebra A e K is called K-non-removable if for any 3uperalgebra B d A, B e K, the ideal I is contained in a proper ideal of 3. Otherwise the ideal I is said K-removable. The latter means that there is an algebra B e K with A c B, and there are elements a^ e I, b^ e B t i = 1,...,n, such that

5 citations

Journal Article•10.1515/DEMA-1978-0320•
The secretary problemthe case with memory for one step

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Beniamin Goldys
01 Jul 1978-Demonstratio Mathematica

5 citations

Journal Article•10.1515/DEMA-1978-0321•
On quasi-invariance of product measures

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Wlodzimierz Smoleáski
01 Jul 1978-Demonstratio Mathematica

5 citations

Journal Article•10.1515/DEMA-1978-0311•
Decomposition of quasi-kahler manifolds which satisfy the first curvature condition

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M. Barros, A. Ramirez
01 Jul 1978-Demonstratio Mathematica

4 citations

Journal Article•10.1515/DEMA-1978-0106•
An analogue of harnack's inequality for discrete superharmonic functions

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Andrzej Schinzel
01 Jan 1978-Demonstratio Mathematica
TL;DR: Verblunsky and Duffin this paper proved the existence of an absolute constant A( < 50) such that o every function f(p) defined on the integral lattice Z satisfying the equation A f ( p ) = f (p + e 1 ) + f( p-e^) + f p + e 2 )+ f p e 2 ), 4f (p) = 0, e1 = (1,0), e 2 = (0,1) and positive in the disc D(o,R) satisfies the inequalities |f(
Abstract: This inequality has been extended to discrete harmonic functions by S.Verblunsky [8] and R.Duffin [1]. They have proved the existence of an absolute constant A(< 50) such that o every function f(p) defined on the integral lattice Z satisfying the equation A f ( p ) = f ( p + e 1 ) + f(p-e^) + f ( p + e 2 ) + f ( p e 2 ) 4f(p) = 0, e1 = (1,0), e 2 = (0,1) and positive in the disc D(o,R) satisfies the inequalities |f(e^) fi.o)|< | f(o). (j = 1,2).

4 citations

Journal Article•10.1515/DEMA-1978-0202•
On the equivalence of certain relations of tangency of arcs in metric spaces

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J. Grochulski, M. Tkacz, T. Konik
01 Apr 1978-Demonstratio Mathematica
TL;DR: In this article, the authors consider the connection between the tangency of arcs in general metric spaces and the notion of a sphere and a b a l l l in the space (Ε, 1 ).
Abstract: Introduction In the present paper-we consider the connection between r e l a t i o n s of tangency of arcs in general metric spaces. W.Wal i s z e w s k i in [5] gave the d a f i n i t i o n of tangency of se ts in a general ized metric space (E, 1 ) . Here E denotes a set and 1 i s a non-negative r e a l funct ion defined on the Cartesian product Eo* EQ, where E0 i s a family on non-empty subsets of the set E. Under some assumptions, the funct ion 1 induces a metric lQ(x, ,y) = l ( ( x j , [ y ] ) on the set E, which allows us to def ine the notions of a sphere and a b a l l in the space (Ε , 1 ) . According to t h i s d e f i n i t i o n a set Ae BQ i s (a, b) tangent of order k to the se t Be EQ at a point ρ of the space (E, 1) i f the pair (A, B) i s (a, b) concentrated at the point ρ in the considered space and we have

4 citations

Journal Article•10.1515/DEMA-1978-0124•
SOME REMARKS ON COVERING OF BOUNDED SUBSETS OF THE EUCLIDEAN n-SPACE WITH SETS OF SMALLER DIAMETER

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Karol Borsuk
01 Jan 1978-Demonstratio Mathematica
TL;DR: In this paper, the problem of finding the union of n+1 sets of diameter less than 6' has been considered and the answer has been established only in the case n < 3.
Abstract: The conjeoture (see [ 3 ] ) that every bounded subset A of the Euclide-an n-space En with pos i t i ve diameter 6'(A) i s the union of n+1 sets each of diameter less than ¿¡(A) has been considered by many authors ( in part icular by W.G.Boit i a n s k i j [1] and [ 2 ] , H.G. Eggleston [4 ] , B. Gale [ 5 ] , B. Griinbaum [6 ] , H. Hadwiger [ 7 ] , H. Lenz [ 8 ] ) and has been establ ished only in the case n < 3. In the present note, I consider another question of a s imi lar character. Let A be a subset of E*1 with diameter 1 and l e t a. be a r e a l number such that
Journal Article•10.1515/DEMA-1978-0302•
On some relations of tangency of arcs in metric spaces

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J. Grochulski, T. Konik, M. Tkacz
01 Jul 1978-Demonstratio Mathematica
TL;DR: In this article, the Archimedean tangent of order problem is considered in a metr ic space. But the problem is not defined in terms of the point p of the space.
Abstract: This r e l a t i o n w i l l be ca l l ed the r e l a t i o n of ( a , b ) tengency of s e t s of order k a t the point p . If (A,B) € T ^ ( a , b , k , p t h e n we sh&ll say tha t the set A i s l a , b ) tangent of order k at the point p to the set B. There a r i s e s the fol lowing ques t ion: i f the s e t s A,B 6jS0 are ( a ,b ) tangent of order k a t the point p of the space (£ | l ) » then when these s e t s are (a\", b') tangent of order k a t the point p of t h i s space? In the present paper we consider t h i s problem in a metr ic space (E,p) f o r r e c t i f i a b l e a r c s having the Archimedean proper ty a t the point p and f o r r e a l f unc t ions def ined by the e q u a l i t i e s and ^ l ( A ^ S ( p , r ) r ( r ) , B ^ S , ( p f r ) t { r ) ) -
Journal Article•10.1515/DEMA-1978-0410•
SUR LA r-CONTINUITÉ DES FONCTIONS DE DEUX VARIABLES

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Zbigniew Grande
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this paper, the authors present a topological analysis of ensembles in terms of the topology of the environment and the characteristics of the ensembled topologies, which is based on the mesure of Lebesgue.
Abstract: Désignons par E l ' e s p a c e des nombres r é e l s e t par l ' e s p a c e E ir S. Un ensemble A c E es t d i t r -ouvert l o r s q u ' i l es t l a somme d'une f a m i l l e d'ensembles étant du type Fget G^ e t d-ouverts (un ensemble e s t d i t d-ouvert l o r s que chacun de ses points e s t son point de d e n s i t é ) . La f a mi l le R de tous l e s ensembles r o u v e r t s es t une tropologie examinée dans le t r a v a i l [$]• Dans le t r a v a i l [3] l ' a u t e u r montre encore une autre topologie (c R) t e l l e ^ue toutes l e s fonct ions continues presque partout relat ivement à l a mesure de Lebesgue e t approximativement continues sont cont inues par rapport à c e t t e t o p o l o g i e . Cette topologie se compose de tous l e s ensembles presque ouverts (un ensemble A c E es t d i t presque ouvert l o r s q u ' i l e s t d-ouvert e t mi(A) = m(Int(A)) , où m désigne l a mesure de Lebesgue e t Int(A) désigne l ' i n t é r i e u r de l 'ensemble A. Dans c e t a r t i c l e j 'examine l e s topologies suivantes : R̂ = | a c E 2 : A e s t r o u v e r t } ^ R2 = R * R , où R x R désigne l a topologie ayant comme sa base l a f a m i l l e des ensembles de l a forme A x B, où A,B 6 R;
Journal Article•10.1515/DEMA-1978-0218•
Sur les fonctions a-continues

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Zbigniew Grande
01 Apr 1978-Demonstratio Mathematica
TL;DR: In this paper, it is shown that a fonction is dense in dense dense ensembles, and that the dense ensemble is dense with respect to the fonctions.
Abstract: I . Désignons par R l 'espace des nombres réels et par I l ' i n t e r v a l l e fermé [0 ,1] , D é f i n i t i o n 1. Une fonction f il—-R est dite F-continue lo r squ ' i l existe unje fonction continue g i i — R dont le graphe G(g) est contenu dans l a fermeture Cl(G(f)) du graphe de l a fonction f . R e m a r q u e 1. Soit f i l — R une fonction. S ' i l exis te une fonction continue g : I — R t e l l e que l'ensemble { x c l r f ( x j = g(x)| est dense dans I , l a fonction f est F-continue. D é m o n s t r a t i o n . En e f f e t , comme G(g) c Cl(G(f)4, l a fonction f est dono P-continue. Cependant i l existe une fonction F—continue f : I — R t e l l e que l'ensemble {x e I : f ( χ ) = g(x)} n» est pas dense dans I , quelle que soi t l a fonction continue g : I*-R.
Journal Article•10.1515/DEMA-1978-0419•
On the different definitions of the lower semicontinuity, upper semicontinuity, upper semicompacity, closity and continutiy of the point-to-set maps

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Wiestaw Sobieszek, Pawet Kowalski
01 Oct 1978-Demonstratio Mathematica
Journal Article•10.1515/DEMA-1978-0407•
Bayesian approach to the prediction problem in gamma population

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G. S. Lingappaiah
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this paper, the predict ion problem has been viewed mostly in two different ways, namely, the Bayes approach with poster ior d iord i s t r i b u t i c s t i o n s and the exact version of the problem where more than a pair of samples are used.
Abstract: 1 . Introduction Predict ion problem, which i s r e c e i v i n g much a t t e n t i o n r e c e n t l y , has been viewed mostly in two d i r e c t i o n s . One i s .the c l a s s i c a l approach based on the independence of s t a t i s t i c s and t h e i r exact d i s t r i b u t i o n s . Such i s the case in Lawless [ 9 ] , Paulkenberry [8], Kaminsky, Luks and Nelson [7 J and a lso in Lingappaiah [10] , [i 1] . But, another method, i s the Bayes approach with poster ior d i s t r i b u t i o n s and su i tab le p r i o r s . Such works are seen i n Bancroft and Dunsmore [ l ] , Aitcheson and Dunsmore [2] and Dunsmore [3] , [4] . Our development here i s based on l a s t of these r e s u l t s Dunsmore [4] and Lingappaiah [ 1 1 ] . Our main motivation, here , i s about what can be done where more than a pair of samples are a v a i l a b l e . What we have done here i s to consider the poster ior d i s t r i b u t i o n at a c e r t a i n stage as the prior f o r the next s t a g e , on the l i n e s of Khan [12] and in so doing, we have developed the predict ive d i s t r i b u t i o n f o r an order s t a t i s t i c at the sth stage ((s+1)th sample) and a lso f o r the d i f f e r e n c e of two s t a t i s t i c s at t h i s s tage . We have discussed the variance in each of these two cases in r e l a t i o n to number of s t a g e s . Also , we have evaluated the probabi l i ty i n t e g r a l f o r both the s i t u a t i o n s and p a r t i c u l a r cases are considered f o r i l l u s t r a t i o n s .
Journal Article•10.1515/DEMA-1978-0206•
On some problems concerning subordination and majorization of functions

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Anna Szynal, Jan Szynal
01 Apr 1978-Demonstratio Mathematica
Journal Article•10.1515/DEMA-1978-0220•
On starlike and convex functions of many variables

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Krystyna Dobrowolska, Izydor Dziubiúski
01 Apr 1978-Demonstratio Mathematica
Journal Article•10.1515/DEMA-1978-0209•
On totally umbilical surfaces in some riemannian manifolds

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Wiestaw Grycak
01 Apr 1978-Demonstratio Mathematica
TL;DR: In this article, the submanifold VQ is defined as the fundamental manifold of the manifold VQ, and the manifold is defined in terms of the parameters of the Riemannian manifold Vm.
Abstract: 1. P r e l i m i n a r i e s Let Vm be an m-dimensional Çiemannian mánifold immersed in an n-dimensional Riemannian maaifold V_, and l e t i u
Journal Article•10.1515/DEMA-1978-0406•
Certain reflexive lattices of subspaces of a hilbert space

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Anna Pol-Ṥwirszcz
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this article, it was shown that the set Lat is always a complete sublattice of the lattice £ (H) of a Hilbert space, and that Lat is invariant under every operator in any subset of H such that X = Lat for some e *.
Abstract: let H be a Hilbert space, let £ (H) be the set of all closed linear subspaces of H, and let
Journal Article•10.1515/DEMA-1978-0112•
Boundedness of solutions of some non-linear hyperbolic equations

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Wawrzyniec Sadkowski
01 Jan 1978-Demonstratio Mathematica
TL;DR: In this article, the authors define functions describing the problem in the following way: UJQXI—-R; h1, h 2, r, p : f í -R; g. f ^ f g j R −R; and operators a, fi : C2(fí * I ) -C°(Q * I).
Abstract: 1. Symbols of notation and statement of the problem Let R = (-o^oo), i = <0,00), £2 be the closure of a bounded domain, the boundary of which i s a piecewise smooth surface T,ft c R n . We define functions describing our problem in the following way: UJQXI—-R; h1 , h 2 , r , p : f í —R; g . f ^ f g j R—R and operators a , fi : C2(fí * I ) —C°(Q * I ) . a [ u ] , /3[u] are values of operators a , ft for the function u e I ) , .and c t [u ] (x , t ) , j8 [u](x , t ) are the i r values at the point ( x , t ) . The two well-known operations wi l l be used: grad, div r e s t r i c ted to the set Q t e . g . for x = ( x ^ , . . . , x n ) we have
Journal Article•10.1515/DEMA-1978-0422•
SUR UNE DÉFINITION DES ALGÈBRES DE LUKASIEWICZ ET DE POST D'ORDRE n

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D. Becchio, L. Itarrioz
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this paper, the notion d'algèbre de Lukasiewicz d'ordre n is introduced, i.e., a trivalente of the notion of Post d'ORDRE n.
Abstract: Introduction En 194-1» Moisil [8] a introduit la notion d'algèbre de Lukasiewicz d'ordre n. D'une part ces structures sont des généralisations de la notion d'algèbre de Lukasiewicz trivalente considérée par le même auteur [7] en 1940, mais qui ne sont pas fermées par rapport à l'implication Lukasiewiczienne [3]. D'autre part elles peuvent admettre, dans certains cas, une chaîne de constantes déterminée d'une façon univoque de manière à devenir des algèbres de Post d'ordre n [3]. Dans [4] une définition des algèbres de Lukasiewicz d'ordre n a été donnée, où l'implication intuitionniste joue un rôle essentiel. Bien que cette définition ait été obtenue d'une manière naturelle, étant donnée la littérature existante, elle ne reflète pas, à première vue, certaines propriétés importantes des algèbres de Lukasiewicz d'ordre n. De façon précise, nous pensons à la loi de Kleene [êj
Journal Article•10.1515/DEMA-1978-0214•
Quasi diffusion solution of stochastic differential equations

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Jacek Dabrowski
01 Apr 1978-Demonstratio Mathematica
Journal Article•10.1515/DEMA-1978-0417•
Definability of functions on a finite set by means of compositions of addition and multiplication modulo some prime numbers

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A. O. Uziemlo, L. Żurawska
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this paper, it was shown that every function defined on a f i n i t e set of cardinality Q may be represented as a composition of addition and multipl icat ion modulo prime numbers which divide G and usual addition and mul t ip l i ca t ion.
Abstract: The aim of t h i s paper i s to show that every function defined on a f i n i t e set of cardinal i ty Q may be represented as a composition of addition and mult ipl icat ion modulo prime numbers which divide G and usual addition and mul t ip l i ca t ion . A.V.T. Kuzniecow [ l ] showed that i f n i s prime, then every function defined on = j o , 1 , . . . , n 1 j and with values in t h i s set may be represented as a composition of addition and mult ipl icat ion modulo n. In t h i s paper we gener a l i z e Kuzniecow's theorem to se ts of c a r d i n a l i t y , which i s not prime. Let Q = q .| . . .q r , where i s a non-decreasing r termed sequence of primes. We define a sequence Q 0 , . . . , Q r of natural numbers by
Journal Article•10.1515/DEMA-1978-0322•
How to decrease the combinatory complexity

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Jerzy Trojan
01 Jul 1978-Demonstratio Mathematica
TL;DR: In this paper, the authors consider the problem of approximating a nonlinear scalar equation with one-point iteration without memory and define the sequence of successive approximations for a given integer s, s.
Abstract: Introduction We consider the solution of a nonlinear scalar equation (1) f(x) = 0, where f: Dc£-"-C . Assume that f is analytic in a neighbourhood of a simple zero a , f(a) = 0 4 f' (oc). We approximate ot by an iteration. Suppose that we can compute the standard information on f, i.e. (2) 31 (f,x) = {f(x)t f' (x),..., f(s)(x)} for a given integer s, s We deal with a one-point iteration without memory

Journal Article•10.1515/DEMA-1978-0319•
Boundedness and stability of solutions of some hyperbolic equations

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Wawrzyniec Sadkowski
01 Jul 1978-Demonstratio Mathematica
TL;DR: In this paper, the authors investigated the properties of solutions of the problem of finding the closure of a bounded domain, where the boundary of which is a piecewise smooth surface r t Q c R.
Abstract: In the paper functions are denoted by minuscules and constants are denoted by capitals. Let R = (-°ofoo)f R + = a <0,°° ), Q be the closure of a bounded domain, the boundary of which is a piecewise smooth surface r t Q c R . We consider functions ut Q * H + — — R j a ^ t h^, hg, r, pi Q — — R , i,j = 1,...,n and operators : 0^(52 x R + ) — — — x fi+). oc[u], /3[u] are values of operators oc , /3 for the function u 6 C(Q * S+) and oc[u] (x,t), ¿3[u] (x,t) are their values at the point (x,t). In this paper we Investigate the properties of solutions of the equation
Journal Article•10.1515/DEMA-1978-0424•
ON THE CAUCHY PROBLEM FOR THE n-CALORIC EQUATION AND FOR THE TIME-PLANE

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Jan Musiaiek
01 Oct 1978-Demonstratio Mathematica
TL;DR: In this article, the authors construct a continuous function that is defined f o r t > 0 and a l l l,x 2 which is the so lu t ion u(X) fo r the n -ca lo r io equation (1) P V X ) 0, where n i s a pos i t ive i n t e g e r, n > 2 P « D* + D I D+, I ^ P i P 1 1 1 ), P° = Id ¿2 « in the domain (2) W =
Abstract: _1. Let x = ( x 1 , x 2 ) , X = ( x 1 , x 2 , t ) . In t h i s paper we s h a l l construct a continuous func t ion u = U(X) defined f o r t > 0 and a l l ,x 2 which i s the so lu t ion u(X) f o r the n -ca lo r io equation (1) P V X ) 0, where n i s a pos i t ive i n t e g e r , n > 2 P « D* + D I D+, I ^ P i P 1 1 1 ) , P° = Id ¿2 « in the domain (2) W = Jx : 1^1-=°°» i 1 f 2 r t > o J and s a t i s f i e s the i n i t i a l condit ions (3) Dju(X) = f ^ x ) f o r l £ S s jx^ | x j c oo , j = 1 ,2 , t = ©j, ( 1 = 0 , 1 . . , n , 1 ) . 2. Let Y = (y . , ,y 2 ,8 ) , y = (y . , ,y 2 ) , and l e t r = | x , y | = y ( * 1 y 1 ) 2 + ( x 2 y 2 ) 2 .
Journal Article•10.1515/DEMA-1978-0207•
SUR LES FONCTIONS UNIVALENTES, BORNÉES, SATISFAISANT DEUX AU MOINS Dn - ÉQUATIONS

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Janina Sladkowska
01 Apr 1978-Demonstratio Mathematica
TL;DR: In this paper, an ensemble of points in a space of 2n-1 dimensions is described, where the points are correspondences of fonct ions of the same type.
Abstract: (2) |f (z)| < 1 pour ζ e U. Les points x,, , x 2 , y 2 , . . . , x Q , y a , où x^ = r e j ^ j , y ĵ = ι correspondent aux fonct ions de l a c l a sse S,], forme un ensemble dans l ' e space de 2n-1 dimensions. La c l a s se S^ devient compacte par l ' a d d i t i o n de l a fonction f = 0, a l o r s l 'ensemble l7nu {θ} est fermé. On peut démont r e r que {θ} es t un domaine fermé, topologiquement équ i va lent à l a sphère de 2n-1 dimensions, [5]. Soit F = , x 2 , y 2 , . . . « χ η ι ϊ η ) u n e fonction r é e l l e remplissant l e s condit ions: (A) Έ e s t . d é f i n i e dans l 'ensemble ouvert 0 contenant
Journal Article•10.1515/DEMA-1978-0310•
Remarks on functor categories

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Zbigniew Leszczyóski
01 Jul 1978-Demonstratio Mathematica
TL;DR: In this paper, it was shown that for unitary modules over C the following conditions are equivalent: 1) right projective modules are in fec t ive 2i l e f t project ive module are in function ive 3i l r e f project ives are in functional ive 4i l a s s project ies modules are pro ive.
Abstract: where X®N i s a tensor product of modules over the ca tegory C ( for the de f in i t ion see below J. Let R be a (not necessar i ly commutative) ring with unity. We know that fo r the category of unitary modules over the r ing R the following conditions are equivalent: 1) r ight project ive modules are in fec t ive 2i l e f t project ive modules are in jec t ive 3l r ight in jec t ive modules are project ive 4i l e f t in jec t ive modules are pro jec t ive . Each of these conditions defines a c l a s s of quasi-Frobenius r ings (see [ 2 ] ) . The s i tua t ion i s d i f f e r e n t in the case of the category od. Harada in [3] gave examples from which we may conclude that no implication between points 1) and 3) holds . We show for modules over C that conditions 1) and 2) imply 3) and 4 ) , end that the inverse implication holds, too. In the proof of th i s f ac t we use a cnaracter i sa t ion of loca l ly Noetherian, coherent and perfect functor categor ies -n ( Q . ® M} t e l X
Journal Article•10.1515/DEMA-1978-0414•
ORIENT ABILITY OF n-DIMENSIONAL PROJECTIVE GEOMETRY

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Mieczyslaw Kucharzewski
01 Oct 1978-Demonstratio Mathematica
TL;DR: A e GP(n,R) G and A < B> e GP (n,K) G < B > < A > 6 G as mentioned in this paper, where B is the number of players in the game.
Abstract: A e GP(n,R) G and A < B> e GP(n,K) G < B > < A > 6 G

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