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`(1) The intersection of sets a and B means___ Union means___ They are expressed as___ ? (2) Let set I be a complete set, and set a be a subset of it___ , expressed in descriptive form as___ ?
1. Elements common to AB; all elements contained in AB; as above
2. The set of elements in I other than those in a; as above
If the union of a and B is not equal to B, then the intersection of a and B is not equal to a, and in its inverse proposition, no proposition and inverse no proposition, the true proposition is
Inverse proposition: if the intersection of a and B is not equal to a, then the union of a and B is not equal to B;
No proposition: if the union of a and B is equal to B, then the intersection of a and B is equal to a;
Converse no proposition: if the intersection of a and B equals a, then the union of a and B equals B
As the original proposition and the inverse proposition are correct, all four propositions are true propositions
The intersection, in general, is a set of all elements that belong to a and B, which is called the intersection of a and B_ Remember to do_ , i.e
The common part of intersection anb. Ab
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