Topological linear spaces having the property that some sequentially continuous linear maps on them are continuous, are investigated. It is shown that such properties (and close ones, e.g., bornological-like properties) are closed under large products.
Let be a Baire space, be a compact Hausdorff space and be a quasi-continuous mapping. For a proximal subset of we will use topological games and on between two players to prove that if the first player has a winning strategy in these games, then is norm continuous on a dense subset of . It follows that if is Valdivia compact, each quasi-continuous mapping from a Baire space to is norm continuous on a dense subset of .
Let be the class of Banach spaces X for which every weakly quasi-continuous mapping f: A → X defined on an α-favorable space A is norm continuous at the points of a dense subset of A. We will show that this class is stable under c₀-sums and -sums of Banach spaces for 1 ≤ p < ∞.
The concept of almost quasicontinuity is investgated in this paper in several directions (e.g. the relation of this concept to other generalizations of continuity is described, various types of convergence of sequences of almost quasicontinuous function are studied, a.s.o.).
A function is said to be almost quasicontinuous at if for each neighbourhood of . Some properties of these functions are investigated.