If A is contained in B, then the interior of A is contained in B.

ZioX

Generally, in the literature [tex]\subset[/tex] is synonymous with [tex]\subseteq[/tex].

[tex]\varsubsetneq \not= \subset[/tex]

ZioX	Generally, in the literature [tex]\subset[/tex] is synonymous with [tex]\subseteq[/tex]. [tex]\varsubsetneq \not= \subset[/tex]