Statement 1: If $A\subseteq B$ and $B \subseteq A$ then $A= B$
Statement 2: If $A= B$ then $A\subseteq B$ or $B \subseteq A$
Which of these statements are true?
Statement 1 is standard definition of Equivalence of 2 sets, so always true.
Statement 2 seems to be true but I am not sure.