Set theory - expression describing subset

[tsrgb]

Homework Statement

I have two sets E and L.
I have to show that E is a subset of L, using only complement, union and the empty set.
I.e. all members of E also have to be members or L, but L may contain members not included in E.

Homework Equations

The Attempt at a Solution

Am I right in describing it thus:
complement(complement(E) union L) = Ø

Any help is appreciated.tsrgb

 

[Gib Z]

Its quite easy to work out or check your answers if you draw up a Venn Diagram =]