olemus
selline binaarseos S mingis hulgas, mille puhul kehtib x S y parajasti siis kui y S x selle hulga mis tahes elementide x ja y korral
= the relationship between two elements such that if the first element is associated with the second then the second element is also linked to the first element in a similar fashion.

ülevaateid
https://en.wikipedia.org/wiki/Symmetric_relation
https://www.cuemath.com/algebra/symmetric-relations/
https://miet.ac.in/assets/uploads/cs/Introduction%20and%20types%20of%20Relations.pdf

vt ka
- antisümmeetriline seos