## and its Relations to Modern Analysis and Algebra

was held on August 25–29, 1986 in Prague, Czech Republic. It was organized by the Mathematical Institute of the Czechoslovak Academy of Sciences in cooperation with the Faculty of Mathematics and Physics of the Charles University, the Faculty of Civil Engineering and the Faculty of Nuclear Science and Physical Engineering of the Czech Technical University, the Faculty of Natural Sciences of the Purkyně University, the Institute of Mathematics of the Slovak Academy of Sciences, the Faculty of Mathematics and Physics of the Comenius University and the Association of Czechoslovak Mathematicians and Physicists. Support for the Symposium was also provided by the Pedagogical Faculty of the Purkyně University and the Faculty of Natural Sciences of the Šafárik University.

### Organizing committee

• Z. Frolík (chairman)
• L. Bukovský (vice-chairman)
• M. Hušek (vice-chairman)
• V. Koutník (vice-chairman)
• J. Vilímovský (secretary)
• A. Rázek (treasurer)
• B. Balcar
• J. Hejcman
• K. John
• J. Kolomý
• J. Lukeš
• L. Mišík
• T. Neubrunn
• J. Pelant
• P. Pták
• V. Pták
• A. Pultr
• J. Reiterman
• V. Rodl
• J. Rosický
• M. Sekanina
• P. Simon
• V. Trnková
• P. Vrbová

The Symposium was attended by 220 mathematicians from 29 countries. The scientific programme was prepared by the Program Committee cinsisting of Z. Frolík (chairman), M. Hušek (vice-chairman), B. Balcar and J. Pelant. The programme consisted of 35 lectures invited by the organizing committee and 132 contributed papers presented in three or four parallel sections.

62 papers (invited or contributed) together with 74 abstracts were published in General Topology and its Relations to Modern Analysis and Algebra VI, Proceedings of the Sixth Prague Topological Symposium 1986 (Heldermann Verlag 1988).

### List of countries

The table summarizes the number of participants from individual countries.

 Czechoslovakia 50 Poland 33 USA 22 Germany, Italy 16 USSR, Yugoslavia 12 Canada 8 Hungary 7 Bulgaria, Finland 6 Japan, United Kingdom 5 Austria, Greece, the Netherlands 3 India, Zimbabwe 2 Algeria, Belgium, France, Kenya, Kuwait, Romania, Spain, Switzerland, Turkey 1

### List of communications

The invited talks are in boldface.

 Aarts One dimensional dynamical systems. Abel Topological module-algebras without free maximal closed ideals. Adámek Reflective subcategories of topological spaces, II. Finite intersections. Anderson General topology in the twenty-five years of the Prague symposia. Andrijević On the topology generated by preopen sets. Antosik On double and iterated limits. Arhangelskii Some new approaches, results and problems in the theory of mappings. Artico, Moresco On the structure of fuzzes. Arya, Singal The open cover sum theorem. Atsuji Pseudo- and countably compact spaces and bitopological spaces. Aydin An order relation between fuzzy numbers and its use in fuzzy metric. Baladze On strong shapes of compact G-spaces. Baláž Separate continuity and joint continuity. Balcar, Simon Nondistributivity and disjoint refinement in Boolean algebras. Balogh On Baire and related sets in normal spaces. Banaschewski Stably continuous locales. Bandt On the Hausdorff metric on hyperspaces. Beattie, Butzmann-P. On Choquet spaces. Bella Some remarks on the Novák number. Bensimon The topological space of all extreme points of a compact convex set. Bielawski A selection theorem for open-graph multifunctions. Bjon Convergence structures in infinite-dimensional holomorphy. Błaszczyk A construction of a rigid Boolean algebra. Burzyk An example of a normed non-complete K-space. Butzmann Sequentially determined convergence spaces. Cagliari, Mantovani Localizations in universal topological categories. Cain Countable compactifications. Chaber On the class MOBI. Charalambous Further theory and applications of covering dimension theory of uniform spaces. Charatonik J. J. Continua with property R Charatonik W. J. Open Whitney maps for the hyperspace of the circle. Chvalina On the Michael-Novikov-Castaing type approximation of correspondences. Ćirić Some results on nonlinear quasi-contractions. Comfort Some unsolved problems in topological groups. Di Concilio, Naimpally A nearness approach to extension problems. Császár Á. Multiplicative semigroups of continuous mappings. Czuba A new class of non-contractible continua. Daniels When countably paracompact, locally compact, screenable spaces are paracompact. Davis The strict p-space problem. Dawidowicz Fixed point theorem for a new class of multivalued mappings. Debs Using games in topology. Diamond Images and preimages of rimcompact, almost rimcompact and 0-spaces. Dikranjan Non-completeness measure of convergence abelian groups. Dimitrijević, Kočinac On treelike proximity spaces. Dimov On Eberlein spaces and related classes of spaces. Dobrowolski, Mogilski Countable dimensional skeletoids in the Hilbert cube. van Douwen Groups, maximal topologies and $\beta X$. Dow Reflection and forcing in topology. Downarowicz Some extension of the irrational disc rotation. Drewnowski, Lipecki On some dense subspaces of topological Iinear spaces II. Duchoň Characterization of Fourier transforms. Duda Some theorems concerning span and semispan. Eklund, Gähler Fuzzy convergence. Ewert Multivalued maps into a bitopological space; closed graph and lower semicontinuity. Fabian On projectional resolution of identity on the duals of certain Banach spaces. Fedorchuk On some geometrical properties of the functor of probabilistic measures. Flachsmeyer Topological ortho-posets. Fleischer Regular completion of convergence groups. Frič, Koutník Completions of convergence groups. Frolík Remarks to the development of topological descriptive theory. Gähler Discrete convergence and applications to integral equations. Ganster On the collection of preopen sets in a topological space. Gerlits, Nagy On some convergence properties. Granas A general coincidence theorem for set-valued maps. Grimeisen On a class of filters closed under filtered summation. Gruenhage On the existence of suborderable subspaces. Guia, Arval Some new set topological operators. Haluška On integration in locally converx spaces. Hattori Characterizations of metrizable spaces having transfinite dimension. Hejcman Topological vector group topologies for the real line. Henriksen Spaces of prime ideals. Herrlich Hereditary topological constructs. Hitchcock A generalization of minimal and maximal spaces. Holá Hausdorff metric convergence of continuous functions. Husch Quasi-embeddings. Husová Topologies on space of empirical functions. Hušek, de Vries Compactifications of products of topological semigroups. Idzik A selection theorem. Iliadis Continua that are almost locally a bundle of arcs and the property of universality. Jelič $\xi_B$-dimension function of bitopological spaces. Johnson, Lazarow, Wilczyński Topologies related to sets having the Baire property. Jokl On a generic differentiability of convex functions. Juhász Cardinal functions on large subspaces. Junnila On hereditarily metacompact spaces. Just $\omega^* \times \omega^*$ may not be a continuous image of $\omega^*$. Kalina Measure in the alternative set theory. Katětov On universal metric spaces. Kent, Vainio The category of preordered Cauchy spaces is cartesian closed. Kerre, Ottoy A comparison of the different notions of neighbourhood systems for Chang topologies. Kočinac On radiality of function spaces. Kokk On the spectra of topological module-algebras. Kopperman, Meyer A metrization invariant. Koyama On compacta which are $1$-equivalent to $I^n$. Krupski On homogeneous tree-like continua. Kůrková Topological semantics of modal logic $S4$. Lindström Algebras of holomorphic functions. Lipiński. On relations between continuity, quasi-continuity and cliquishness of maps. Lokucievskii On the approximation of any metric compacta by finite-dimensional metric spaces. Makai k-compactness and ordered spaces. Mańka Generalized notion of the supremum. Marciszewski An infinite compact space $K$ with $C_p(K)$ not homeomorphic to $C_p(K) \times C_p(K)$. Mauldin Random topological objects. Michael Continuous selections avoiding a set. van Mill Local contractibility, cell-like maps, dimension, and Kuratowski's problem. Mogilski Some examples of absorbing sets in the Hilbert space. Mršević On weakly $\theta$-continuous functions. Nedev Inverse selection theorem. Negrepontis Weakly stable Banach spaces. Neubrunn Strongly quasi-continuous multifunctions. Nikiel A continuous partial ordering for images of arcs. Nogura Products of Fréchet spaces. Noll On the open mapping theorem in topological spaces. Nyikos Progress on countably compact spaces. Oja Uniqueness of Hahn-Banach extensions. Oversteegen On atriodic tree-like continua and homogeneous trees. Papadopoulos Exponential laws for function spaces equipped with the quasi uniformity of quasi uniform convergence. Pareek On symmetrizable spaces. Pedicchio De Morgan and strong de Morgan laws in a topos of sheaves. Pelant Remarks on Isbell's semiproducts. Pietsch A historical survey of the theory of infinite determinants. Plaskacz Coincidence of contractive-type pairs. Plewik Remarks on closed mappings. Pochcial Remarks on sequential characterizations of metrizability. Pol Countable dimensional universal sets. Porst On free topological algebras. Pultr Some recent results of the theory of locales. Purisch The orderability of scattered spaces. Reed E. E. Extensions and interval structure. Reed G. M. The intersection topology and normal Moore spaces whose squares are not normal. Riečan On a modification of topological entropy Remus Topological groups without non-trivial characters. Rogers The ends of continua and the hyperbolic plane. Roitman More compact scattered spaces (=superatomic Boolean algebras). Rosický Reflective subcategories of topological spaces Infinite intersections. Salbany Spaces with unique quasi-uniformties. Singal, Nimse z-continuous mappings. Šmarda $T_1$- and $T_2$-locales. Šostak Compactness and connectedness degrees in fuzzy spaces. Stegall Sequences of $k$-analytic functions. Stojaković Some new types of contraction in Menger spaces. Szambien Uniform structures in projective geometry. Tall Topological applications of supercompact and huge cardinals. Tholen Diagonal theorems in topology and elsewhere. Tironi On pseudo-radial and almost-radial spaces. Todorčević Topological aspects of the Ramsey theory for the uncountable. Torunczyk Finite-to-one restrictions of continuous functions. Trnková Representations in categories of continuous structures. Turzański On dyadic spaces. Uspenskij Why compact groups are dyadic? Valov A note on AE(0)-spaces. Vaughan On prime closed filters. Veksler Narrow spaces, products of topological spaces and supertiny sequences of Szymański. van de Vel Invariant arcs and fixed points. Vilímovský, Pelant A new characterization of point-finite uniformities. Vinárek A note on representations of rings by topological spaces. Vojtáš Set-theoretic characteristic versus gaps in convergence of series and $P(\omega)/fin$. Waszak Remarks on convergence in some modular spaces. Weiss Partitioning topological spaces. Wicke Complete exhaustive sieves and games. Williams Maps from compact $X$ to itself. Wong A $G_\delta$-theorem for the homeomorphism space of $n$-balls. Yajima On perfect images and subspaces of certain products and their metrizations. Yusufov Open mappings. Zanolin A quotient-type construction of convergence groups. Živanovic Sžimajuščie kompakty. Žižovic Some treelike maps. Zsidó A continuous selection problem in the extreme boundary theory.

### Photos

The collection comes from an album of P. Simon. It contains mostly the invited speakers during their talks.