 Solution

ID: past-exam-of-the-year-1-of-the-computer-science-course-of-the-university-of-oxford/2018/discrete-mathematics-continuous-mathematics-and-probability/1/b/ii/solution

False. Take the sets

A = {1}

B = \emptyset

and

C = {1}

. Both unions with

C

equal

{1}

, although

A \neq = B

. Taking a union with

C

conceals which of its elements belonged to the original set.

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