관계,relation

관계,relation (rev. 1.23)

정의: 집합,set(들)의 cartesian product(곱집합,product_set, VG: 곱집합,product_set )의 부분집합,subset. (mw)

Sub:

// 일단 degree(curr 디그리,degree) / arity(arity) / 대상 집합들의 개수 / .... 기준으로

0인 경우도 존재.
https://en.wikipedia.org/wiki/Relation_of_degree_zero
"relation of degree zero, 0-ary relation, or nullary relation"
// arity / 디그리,degree / 영,zero

1 unary_relation ?


(misc delme) 철자 혼동 주의: 이하 (in)finitiary 가 아니라 (in)finitary 임

(유한한 수)
finitary_relation =,finitary_relation . finitary_relation
finitary relation
WpEn:Finitary_relation
Ggl:finitary relation
WtEn:finitary_relation x 2023-08-22
"finitary relation"

그럼 infinitary_relation 라는 것도 존재?
∞ infinitary_relation
infinitary relation
...
ndict x 2023-08-22
Naver:infinitary relation
Bing:infinitary relation
Google:infinitary relation
https://en.wikipedia.org/wiki/Infinitary_relation - doesn't exist - 2023-08-22
별도 항목으로 따로 둔 사전/백과/위키는 없는 듯 하고 대개 finitary_relation 에서 같이 설명함.
See:
https://math.libretexts.org/Bookshelves/Combinatorics_and_Discrete_Mathematics/A_Cool_Brisk_Walk_Through_Discrete_Mathematics_(Davies)/03:_Relations/3.4:_Finite_and_infinite_relations
직접 관련된건 아니지만 see also:
https://en.wikipedia.org/wiki/Infinitary_combinatorics
rel:
무한집합,infinite_set
"infinitary relation"

-1, -2, ..., 유리수, 실수 이런건 meaningless? cardinal_number에만 의미있음? or expandable?

....

inverse_relation =,inverse_relation . inverse_relation
inverse relation
인버스관계
역관계 ?



satisfaction_relation =,satisfaction_relation . satisfaction_relation
{
satisfaction relation

REL
satisfaction =,satisfaction . satisfaction {
만족

이것보다 관련표현인 satisfiability 가 매우 자주 보인다... 아래.

관련표현
satisfactory adj. 만족스러운
satisfiability n. - 보통 '충족가능성'으로 번역하는 게 대세인듯. // or 충족여부 만족가능성 만족여부 ??
WtEn:satisfiability = https://en.wiktionary.org/wiki/satisfiability
esp Boolean_satisfiability Boolean satisfiability (이걸 줄여서 SAT ?)
satisfiability_problem =,satisfiability_problem . satisfiability_problem
satisfiability problem (이걸 줄여서 SAT ?)
rel conjunctive_normal 논리곱 정규형 ..
Sub
2-SAT
3-SAT
4-SAT etc
the first known NP-complete problem (Stephen_Cook 1971)
https://mathworld.wolfram.com/Satisfaction.html
}




many-to-many_relation =,many-to-many_relation . many-to-many_relation
{
다대다 관계?


relational_structure =,relational_structure . relational_structure
{
relational structure
WtEn:relational_structure (x 2023-08-15)
https://xlinux.nist.gov/dads/HTML/relational.html


https://proofwiki.org/wiki/Definition:Relational_Structure
aka: relational_system =,relational_system . relational_system { relational system AKA: relational_structure. https://mathworld.wolfram.com/RelationalSystem.html Ggl:relational system }
endorelation 으로 정의함. 그게뭐야? not in ndict. 구글해보니 aka homogeneous_relation.

https://ncatlab.org/nlab/show/relational structure


homogeneous_relation =,homogeneous_relation . homogeneous_relation
endorelation =,endorelation . endorelation
{
homogeneous relation
AKA
endorelation

"on a set X is a binary_relation between X and itself" (we)
즉 동일 집합간 이항관계,binary_relation - cartesian product $\displaystyle X\times X$ 의 subset.


symmetric_relation =,symmetric_relation =,symmetric_relation . symmetric_relation
WtEn:symmetric_relation x(2023-08-15)
https://en.wikipedia.org/wiki/Symmetric_relation
symmetric relation
대칭관계 ?
KmsE:symmetric relation
Ggl:symmetric relation
"symmetric relation"
Up: 대칭성,symmetry

relation symbol
relation_symbol =,relation_symbol =,relation_symbol . relation_symbol
{
relation symbol
aka: = predicate_symbol = predicate_letter



Bing:relation symbol
Ggl:relation symbol
"relation symbol"
}


reflection_relation
reflection relation
https://mathworld.wolfram.com/ReflectionRelation.html

translation_relation
translation relation
https://mathworld.wolfram.com/TranslationRelation.html
짧고 쉬움

recurrence_relation
recurrence relation
https://mathworld.wolfram.com/RecurrenceRelation.html
REL
"When ..., known as recurrence_equation { https://mathworld.wolfram.com/RecurrenceEquation.html } s, or sometimes difference_equation s"
(VG: 점화식,recurrence_relation exists .... 다만 페이지를 점화관계,recurrence_relation recurrence_equation로 나눌 생각을 나도 하는 중.)

universal_relation =,universal_relation . universal_relation
{
universal relation



closure_relation =,closure_relation . closure_relation
{


..... ADDHERE ......

분야: relation theory ? relational theory ?

relation theory
"relation theory"

Up:
relation_theory =,relation_theory . relation_theory
{
관계론 관계이론
WtEn:relation_theory
KmsE:relation



... aka relational_theory ?
2023-08-15:
WpEn:Relational_theory - No, [https]nlab에서 여기로 링크했으나 아님.
WpEn:Relation_theory - 페이지없음.

MKLINK

arity

arity =,arity . arity
{
WpEn:Arity - "is the number of arguments or operands taken by a function, operation or relation" 즉 함수,function 펑션,function 연산,operation 관계,relation가 가지는 성질. 자료구조,data_structure or ADT : 배열,array등도?

0 nullary
1 unary
2 binary
3 ternary
일반적으로 n-ary


비슷? cmp.

relation vs correspondence