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1. The solution of the inequality x <= 1 is semi-infinite segment A = (,].
2. The solution of the inequality x <= 10 is semi-infinite segment B = (,].
3. The solution of the inequality system x<= 1 OR x <= 10 is semi-infinite segment A U B = (,],
which is a UNION of the sets A and B, introduced in n.n.1 and 2. Notice the conjunction "OR" (!)
4. The solution of the inequality system x<= 1 AND x <= 10 is semi-infinite segment A n B = (,],
which is an INTERSECTION of the sets A and B, introduced in n.n.1 and 2. Notice the conjunction "AND" (!)
5. In Math, every word matters and counts.
In Math problem formulation EACH WORD must be correct and correctly used (and correctly understood, as well).