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numbers and algebraic expressions
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elements of statistics
kropki game

Union: A ∪ B. The Union of intervals A and B is the interval of all numbers which are in A, in B, or in both A and B. Example. A = (1,3], B = [2,4), A ∪ B = (1,4). Intersection: A ∩ B. The Intersection of intervals A and B is the interval of all numbers which are in both A and B. Example. A = (1,3], B = [2,4), A ∩ B = [2,3]. Difference: A ∖ B. The Difference of intervals A and B is the interval of all numbers which are in A but not in B. Example. A = (1,3], B = [2,4), A ∖ B = (1,2). Complement: A'. The Complement of interval A to reals is the interval of all numbers which are not in A. Examples. A = (1,3], A' = (-∞,1) ∪ (3,∞).