aleph number
Sign in to saveAlso known as ALEF SYMBOL, ℵ, aleph symbol, alef number
alef symbol (U+2135) or aleph, written left-to-right as the mathemical symbol ‹ℵ› for the first transfinite cardinal (countable); ordered sequence of transfinite numbers used to represent the cardinality (or size) of infinite countable sets
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Encyclopedic overview
Aleph-nought, aleph-zero, or aleph-null, the smallest infinite cardinal number
In mathematics, particularly in set theory, the aleph numbers are a sequence of numbers used to represent the cardinality (or size) of infinite sets. They were introduced by the mathematician Georg Cantor and are named after the symbol he used to denote them, the Hebrew letter aleph (ℵ).
Excerpted from Wikipedia’s “aleph number” article, available under the CC BY-SA 4.0 licence.