Let . Define a relation on by if and only if . If is the number of elements in , and and are the minimum numbers of ordered pairs that must be added to to make it reflexive and symmetric respectively, then is equal to:
Answer: 12
Step-by-step solution
Step 1: Determine the relation R and its size l
The relation is defined for elements in set such that is the maximum of and . We need to find all ordered pairs that satisfy this condition for each . We will then count the number of elements in , which is .
Step 2: Calculate the elements of R
For each : - If , , so . - If , , so . - If , , so . - If , , so . - If , , so . - If , , so . Thus, . The number of elements in is .
Step 3: Determine m for reflexivity
For a relation to be reflexive, every element must have . The set . The reflexive pairs are . From , we have . The missing reflexive pairs are . Therefore, pairs must be added to make reflexive.
Step 4: Determine n for symmetry
For a relation to be symmetric, if , then must also be in . We check each pair in : - , but . So, must be added. - , but . So, must be added. - , but . So, must be added. - , and . No addition needed. - , and . No addition needed. - , and . No addition needed. Therefore, pairs must be added to make symmetric.
Step 5: Calculate l + m + n
We have found , , and . Now we sum these values to get the final answer.
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