Need help with this proof about set relations

In summary, the proof states that for a binary relation R on a set A and its transitive closure R^t, for all x and y in A, xR^t y if and only if there exists a sequence of elements of A such that xRy and yR^t z for all z in the sequence, and the last element of the sequence is y.
  • #1
coasterguy10
1
0
1. I am triying to write a proof that states. Let R be a binary relation on a set A and let R^t be the transitive closure of R. Prove that for all x and y in A, xR^t y if and only if, there is a sequence of elements of A, say X1, X2,..., Xn, such that X= X1, X1RX2,... Xn-1RXn, and Xn = y.

Im not very good with proofs and this one just has me stumped. Any help is appreciated


 
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  • #2
. Proof: Let x and y be elements of A. First, suppose xR^t y. By definition, this means that there exists a sequence of elements of A (X1, X2, ..., Xn) such that X1RX2, X2RX3, ..., X(n-1)RXn, and Xn = y. Now, for the other direction, suppose there exists a sequence of elements of A (X1, X2, ..., Xn) such that X1RX2, X2RX3, ..., X(n-1)RXn, and Xn = y. Then, by definition, xR^t y. Therefore, we can conclude that xR^t y if and only if there is a sequence of elements of A, say X1, X2,..., Xn, such that X= X1, X1RX2,... Xn-1RXn, and Xn = y.
 

Related to Need help with this proof about set relations

1. What is a set relation?

A set relation is a way of describing the relationship between two sets, usually denoted by an arrow. It indicates how the elements of one set are related to the elements of another set.

2. How do I prove a set relation?

To prove a set relation, you must show that for every element in one set, there is a corresponding element in the other set. This can be done using mathematical techniques such as direct proof, contradiction, or induction.

3. What are the different types of set relations?

There are several types of set relations, including subset, equal, proper subset, and equivalence. Each type has its own characteristics and requirements for proof.

4. Can a set have more than one relation?

Yes, a set can have multiple relations. For example, a set of numbers can have a subset relation, an equal relation, and a proper subset relation with other sets of numbers.

5. Are set relations transitive?

Some set relations, such as subset and equal, are transitive, meaning that if A is related to B and B is related to C, then A is also related to C. Other relations, like proper subset and equivalence, are not transitive.

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