Question

Sets. What the difference between \(X \subset Y\) and \(X\subseteq Y \)

Answer 1

The first indicates that X is a proper subset of Y, i.e. that X is a subset of Y that is not equal to Y.

Answer 2

it depends...some books say they are the same...others don't

Answer 3

But yeah ^, I've never really seen anybody get too upset about it in practice....

Answer 4

\[X\subsetneq Y\]

some use this notation

Answer 5

in the first: X is subset of Y but they cant be equal
in the second X &Y may be the same