Suppose that $\displaystyle \displaystyle \tau 1 \mbox and \quad \tau2 \mbox \quad are \quad \quad \quad topologies \quad on \quad a set X \quad with \quad \tau1 \subset \tau2 . \mbox \quad if A \subset X \quad$

$\displaystyle \mbox prove \quad that : \quad \overline{A}^2 \subset \overline {A}^1 \mbox \quad where \overline {A}^1 \mbox is \quad the \quad clousre $ $\displaystyle \quad of A \quad in (X, \tau1 ) \quad \overline {A}^2 \mbox is \quad the \quad clousre \quad of A \quad in (X,\tau2) $