- is
countable if
either it is
finite or it can be made in one to one
correspondence with the set of
natural numbers. Equivalently, a set is
countable if...
- topology, a second-
countable space, also
called a
completely separable space, is a
topological space whose topology has a
countable base. More explicitly...
- ) = 0. {\displaystyle \mu (\varnothing )=0.}
Countable additivity (or σ-additivity): For all
countable collections { E k } k = 1 ∞ {\displaystyle...
- a
branch of mathematics, a first-
countable space is a
topological space satisfying the "first
axiom of
countability". Specifically, a
space X {\displaystyle...
- mathematics, an
axiom of
countability is a
property of
certain mathematical objects that ****erts the
existence of a
countable set with
certain properties...
-
ordered set X is said to
satisfy the
countable chain condition, or to be ccc, if
every strong antichain in X is
countable.
There are
really two conditions:...
- The
cocountable topology, also
known as the
countable complement topology, is a
topology that can be
defined on any
infinite set X {\displaystyle X} ...
- are
countable.
Proof of
first theorem: If P(α) = ∅ for some
index α, then P′ is the
countable union of
countable sets. Therefore, P′ is
countable. The...
- The
axiom of
countable choice or
axiom of
denumerable choice,
denoted ACω, is an
axiom of set
theory that
states that
every countable collection of non-empty...
- in Wiktionary, the free dictionary. In linguistics, a
count noun (also
countable noun) is a noun that can be
modified by a
quantity and that
occurs in...
