Surreal numbers

E29943

Surreal numbers are a class of numbers introduced by John H. Conway that form an extensive ordered field encompassing the real numbers, infinite quantities, and infinitesimals within a unified framework.

All labels observed (6)

Label Occurrences
Surreal numbers canonical 3
Conway normal form 1
Conway numbers 1

How this entity was disambiguated

Statements (48)

Predicate Object
instanceOf Conway number
number system
ordered field
proper class
alternativeName Surreal numbers
surface form: Conway numbers
birthProcess numbers are created in stages indexed by ordinals
constructedFrom left set and right set of earlier numbers
containsAsSubfield ordinal numbers
real numbers
containsElement -1
0
1
1/ω (a positive infinitesimal)
all dyadic rationals
all ordinal numbers
all real numbers
ω (first infinite ordinal as a number)
definedBy transfinite recursion
extends ordered fields
real numbers
generalizes Dedekind-complete ordered fields
hasCanonicalForm Surreal numbers self-linksurface differs
surface form: Conway normal form
hasOrderType proper class length
hasProperty every set of surreals has a greatest lower bound
every set of surreals has a least upper bound
no maximal element
no minimal element other than zero
real-closed field
totally ordered
hasSubset day-n numbers (numbers born on day n in the construction)
includes infinite numbers
infinitesimal numbers
introducedBy John H. Conway
surface form: John Horton Conway
introducedInPublication On Numbers and Games
introducedInYear 1974
isClassOf all numbers generated from the empty set by Conway’s rules
isModelOf ordered field axioms
real-closed field axioms
relatedConcept Hahn series
hyperreal numbers
nonstandard analysis
satisfiesCondition every left element is less than every right element
supportsOperation addition
division
exponentiation (partial)
multiplication
subtraction
usedIn combinatorial game theory

How these facts were elicited

Referenced by (8)

Full triples — surface form annotated when it differs from this entity's canonical label.

John H. Conway notableWork Surreal numbers
Donald E. Knuth notableWork Surreal numbers
this entity surface form: Surreal Numbers
Surreal numbers alternativeName Surreal numbers
this entity surface form: Conway numbers
Surreal numbers hasCanonicalForm Surreal numbers self-linksurface differs
this entity surface form: Conway normal form
Horton notableWork Surreal numbers
subject surface form: John Horton Conway
On Numbers and Games topic Surreal numbers
this entity surface form: surreal numbers
John notableWork Surreal numbers
subject surface form: John H. Conway
Part One: Numbers relatedConcept Surreal numbers
this entity surface form: Conway surreal numbers