Math 2.0

Mathematical logic and foundations Definition

Symmetric relation

Builds on Binary relation

Definition

Let RR be a binary relation on a set AA. The relation RR is symmetric when, for all a,b∈Aa, b \in A, aRba \mathrel{R} b implies bRab \mathrel{R} a.

Remarks

Equality is symmetric. The relation ≤\le on ℝ\mathbb{R} is not symmetric, because 1≤21 \le 2 but not 2≤12 \le 1. A relation RR is symmetric exactly when it is equal to its converse.

Reading path

To understand this page from the ground up, read these 11 pages in order. The foundations come first.

Show the path as a graph
Each page uses the pages above it. The colour of the bar on a box shows how strong the evidence is, and the box also gives it as text. The list has the same pages.
  • no evidence level
  1. Element definition
  2. Proposition concept
  3. Set definition
  4. Implication definition
  5. Predicate definition
  6. Ordered pair definition
  7. Universal quantifier definition
  8. Cartesian product definition
  9. Subset definition
  10. Binary relation definition
  11. Symmetric relation definition

Where this leads

67 pages build on this one.

Further reading

  1. Web https://en.wikipedia.org/wiki/Symmetric_relation, lead section
About this page
Tag0N9SA25Z3V
URIm2://0N9SA25Z3V
Kinddefinition
WritingW1 stated
MSC03E20
DefinesSymmetric relation
UsesBinary relation

Markdown · JSON · Edit on GitHub

What this page needs for W2

  • edge instance_of in: one example (0 of 1)
  • edge not_instance_of in: one non-example that fails one clause (0 of 1)

The writing levels say how complete the text of a page is. They do not measure its truth.

What links here

Used by