Properties of relations

 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive R is reflexive iff (a,a) Î R for all a Î dom(R)

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric R is symmetric iff whenever (a,b) Î R then (b,a) Î R for all a,b Î dom(R)

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric
bullet Anti-symmetric R is anti-symmetric iff whenever (a,b) Î R then not (b,a) Î R for all a,b Î dom(R)

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric
bullet Anti-symmetric
bullet Transitive R is transitive iff whenever (a,b) Î R and (b,c) Î R then (a,c) Î R for all a,b,c Î dom(R)

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric
bullet Anti-symmetric
bullet Transitive
bullet Equivalence relations an equivalence relation is a relation which is reflexive, symmetric and transitive

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric
bullet Anti-symmetric
bullet Transitive
bullet Equivalence relations
bullet Partial orders a partial order is a relation which is anti-symmetric and transitive

Control bar


















































 

CS 446: Automata Theory
Lecture #2: Review of Relevant Mathematics

Properties of relations
bullet Reflexive
bullet Symmetric
bullet Anti-symmetric
bullet Transitive
bullet Equivalence relations
bullet Partial orders
bullet Total orders if every pair of elements in a partially-ordered set is comparable under the partial order, we say that it is totally ordered

Control bar