Possible Duplicate:
Uncountable minus countable set is uncountable
Proposition:
Suppose A is a countable subset of an uncountable set B. Show that B - A is uncountable.
Please help.
Possible Duplicate:
Uncountable minus countable set is uncountable
Proposition:
Suppose A is a countable subset of an uncountable set B. Show that B - A is uncountable.
Please help.
Suppose that $B-A$ is countable. Now we find that the union of $B-A$ and $A$ which is $B$ is countable (contradiction)