82 research outputs found
Uniformizable functional Alexandroff spaces
In the following text we show that the Alexandroff space is uniformizable
if and only if the collection of all smallest neighbourhoods is a partition of
. Moreover the Alexandroff space is uniformizable and functional
Alexandroff (primal) if and only if the collection of all smallest
neighbourhoods is a partition of into its finite subsets.Comment: 8 page
Set-theoretical entropies of weighted generalized shifts
In this paper for a finite field , a nonempty set , a self--map
and a weight vector , we
show that the set--theoretical entropy of the weighted generalized shift
is either zero or
, moreover it is equal to zero if and only if
is quasi--periodic. On the other hand after
characterizing all conditions under which
is of finite fibre, we
show that the cotravariant set--theoretical entropy of the finite fibre
depends only on
and . In final sections we study the restriction of
to the direct sum
- β¦