Hello Let A, B and C be 3 sets. Prove that: if x belongs to (A-B)-C then x belongs to A-C using: a)direct proof. b)proof by contraposition thank you
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Originally Posted by qwerty321 Hello Let A, B and C be 3 sets. Prove that: if x belongs to (A-B)-C then x belongs to A-C using: a)direct proof. b)proof by contraposition thank you a) \ b) \ \ \ Thus \ \ \ Which is proof of the contrapositive.
when you pu the little c above A or B, what do u mean? and for the contrapositivity how did u pass from x belongs to A^cUC to A^cUBUC? thank you
Originally Posted by qwerty321 when you pu the little c above A or B, what do u mean? and for the contrapositivity how did u pass from x belongs to A^cUC to A^cUBUC? thank you A^c stands for A complement. Since .
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