Word.ws English Dictionary

epsilon number

epsilon number noun: any (necessarily transfinite) ordinal number α such that ω^α = α; (by generalisation) any surreal number that is a fixed point of the exponential map x → ωˣ.

Noun

epsilon number (plural epsilon numbers)

  1. Any (necessarily transfinite) ordinal number α such that ω^α = α; (by generalisation) any surreal number that is a fixed point of the exponential map x → ωˣ.
    • More generally, the epsilon numbers are the ordinals #92;varepsilon for which #92;varepsilon#61;#92;omega#92;varepsilon. The smallest epsilon number is #92;varepsilon#95;0. It is a countable ordinal, being the countable union of countable sets. By the Veblen fixed-point theorem, the class of...1977, Herbert B. Enderton, Elements of Set Theory, Elsevier (Academic Press), page 240
    • We show that the associated ordinals are the #92;varepsilon#95;0th epsilon number and the first #92;varepsilon#95;0-critical number, respectively.1981, The Journal of Symbolic Logic, Association for Symbolic Logic, page 17

Forms of epsilon number

pluralepsilon numbers

Origin of epsilon number

From the Greek letter ε (“epsilon”), used to denote the numbers.

Questions about epsilon number

What does epsilon number mean?
Epsilon number means any (necessarily transfinite) ordinal number α such that ω^α = α; (by generalisation) any surreal number that is a fixed point of the exponential map x → ωˣ.
What part of speech is epsilon number?
Epsilon number is a noun.
What is the plural of epsilon number?
The plural of epsilon number is epsilon numbers.

Words near epsilon number in the dictionary

  1. epsilometer
  2. epsilometers
  3. epsilometric
  4. epsilon
  5. epsilon iron
  6. epsilon number
  7. epsilon numbers
  8. Epsilon Pegasi
  9. Epsilon Ursae Majoris
  10. Epsilon variant
  11. epsilon-machine

Source and license

Adapted from Wiktionary: epsilon number (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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