On generalized whitney mappings
On hereditary and product-stable quotient maps
It is shown that the quotient maps of a monotopological construct A which are preserved by pullbacks along embeddings, projections, or arbitrary morphisms, can be characterized by being quotient maps in appropriate extensions of A.
On homotopically regular mappings of manifolds
On interior monotone mappings.
On inverse limits of (2k+m+1)-disk bundle maps
On inverses of almost continuous bijections
On locally H-closed spaces and the Fomin H-closed extension
On locally s-closed spaces.
On maps: Continuous, closed, perfect, and with closed graph.
On maps of spaces determined by countable subspaces
On maps which are perfect with respect to the Hewitt realcompact extension
On medial properties of maps
On minimal Hausdorff and minimal Urysohn functions
In this article, we extend the work on minimal Hausdorff functions initiated by Cammaroto, Fedorchuk and Porter in a 1998 paper. Also, minimal Urysohn functions are introduced and developed. The properties of heredity and productivity are examined and developed for both minimal Hausdorff and minimal Urysohn functions.
On monotone and pointwise splittability
On monotone mappings of continua
On multivalued quotient mappings
On multivalued quotient mappings.
On N. Noble's theorems concerning powers of spaces and mappings
On open light mappings
Whyburn has proved that each open mapping defined on arc (a simple closed curve) is light. Charatonik and Omiljanowski have proved that each open mapping defined on a local dendrite is light. Theorem 3.8 is an extension of these results.
On open maps of Borel sets
We answer in the affirmative [Th. 3 or Corollary 1] the question of L. V. Keldysh [5, p. 648]: can every Borel set X lying in the space of irrational numbers ℙ not and of the second category in itself be mapped onto an arbitrary analytic set Y ⊂ ℙ of the second category in itself by an open map? Note that under a space of the second category in itself Keldysh understood a Baire space. The answer to the question as stated is negative if X is Baire but Y is not Baire.