Adverb
In a countable manner; in a way that can be counted.
(mathematics) In a way that can be put into one-to-one correspondence with the natural numbers or any subset thereof.
Source: en.wiktionary.orgA complete binary tree * In the infinite complete binary tree, every node has two children (and so the set of levels is countably infinite ). Source: Internet
A distribution that has zero probability at countably many points on the real line and has a Gaussian shape everywhere else on the real line is likewise mesokurtic. Source: Internet
As noted above, this terminology is not universal.: Some authors use countable to mean what is here called countably infinite, and do not include finite sets. Source: Internet
A σ-locally finite base is a base which is a union of countably many locally finite collections of open sets. Source: Internet
Completely metrizable spaces can be characterized as those spaces that can be written as an intersection of countably many open subsets of some complete metric space. Source: Internet
;Countably compact: A space is countably compact if every countable open cover has a finite subcover. Source: Internet