- In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set.
- 2 John in Greek (ancientlibrary.net)
At only thirteen verses, 2 John is among the shortest books of the Greek New Testament. Written in Koine Greek in the first century AD and traditionally attributed to John, who styles himself the elder, it addresses ‘the elect lady and her children’ — most likely a church — urging love and obedience, and warning against deceivers who deny Christ’s coming in the flesh.