- #1
kingerd
- 14
- 0
ok i don't know why i can't grasp this and i feel so stupid...
here's an example in the book which i do get...
Let S denote the set of all nonempty subsets of {1, 2, 3, 4, 5}, and define a R b to mean that a [tex]\cap[/tex] b not equal to [tex]\emptyset[/tex]. The R is clearly reflexive and symmetric. Howerver, R is not transitive since {1, 2} R {2, 3} and {2, 3} R {3, 4} are true, but {1, 2] R {3, 4} is false
but here's two problems that i don't get where i have to state what the special propert(y/ies) are and state whether R is an equivalence relation on S
S = {1,2,3,4,5,6,7,8} and x R y means that x - y is odd
S = {1,2,3,4,5,6,7,8} and x R y means that |4 - x| = |4 - y|
here's an example in the book which i do get...
Let S denote the set of all nonempty subsets of {1, 2, 3, 4, 5}, and define a R b to mean that a [tex]\cap[/tex] b not equal to [tex]\emptyset[/tex]. The R is clearly reflexive and symmetric. Howerver, R is not transitive since {1, 2} R {2, 3} and {2, 3} R {3, 4} are true, but {1, 2] R {3, 4} is false
but here's two problems that i don't get where i have to state what the special propert(y/ies) are and state whether R is an equivalence relation on S
S = {1,2,3,4,5,6,7,8} and x R y means that x - y is odd
S = {1,2,3,4,5,6,7,8} and x R y means that |4 - x| = |4 - y|