- #1
j9mom
- 31
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Homework Statement
I am very confused on how to prove these set theories. The statements seem to prove themselves just by the definitions of the symbols. For example:
If A is contained or equal to B union C and A intersect B = {} (the empty set) then A is contained or equal to C.
The Attempt at a Solution
What I have is:
Assume that A is contained in or equal to B union C. So, any element X that is in A will also be in either B or C. However, we also assume that A n B is the empty set, there is not element in B that is in A. Hence, any X must be contained in C. Therefore A is contained in or equal to C.
This seems too easy... What am I assuming that i need to prove?