maths.free › Set Theory & Logic › Relations, functions and equivalence
Relations, functions and equivalence
Relations as sets of pairs; reflexive, symmetric, transitive; functions and bijections.
A relation is a set of ordered pairs; an equivalence relation (reflexive, symmetric, transitive) partitions its set into classes; a function is a relation with exactly one output per input. Picture it: "same remainder mod 3" splits the integers into three columns. Think it: a bijection is how we say two sets have the same size, including infinite ones.
Ýüklenen mysal · truth table of p implies q
Truth table of p implies q
Adım adım
- p \Rightarrow q
2 variable(s) → 4 rows. Fill in every combination.
- \
Contingent: true for some inputs, false for others.
Jawaby görkez
Indi sen Bir meseläni saýla, ýa-da ýaz ýa-da özüňi surata çek. Her ädim, bir resim, jogap sorag berlençä gizlenýär.
Şu ýerde ulanylan simwollar
Eň täze düşündirme, surat, we her harpyň manysy üçin her bir simwoly basyň.
Nädip: Relations, functions and equivalence
- 2 variable(s) → 4 rows. Fill in every combination.
- Contingent: true for some inputs, false for others.
Adamlar soraýan soraglar
Are some infinities bigger than others?
Yes. The integers and the rationals can be listed; the real numbers cannot (Cantor's diagonal argument), so there are strictly more reals than integers.
What is the difference between a relation and a function?
A relation pairs inputs with outputs freely; a function is a relation in which every input gets exactly one output.
_Ýaşa Set Theory & Logic
Sets and operationsCardinality and infinityLogic and methods of proof