by 

                                                                                          
                                          MS.C  Taha Guma el turki 

                               Benghazi University department of Mathematics

                                     email: taha 1978_2002@yahoo.com 

  Definition [1]:- 

Let X be any set, τ is not a discrete topology on X then τ is said to be an extremal topology if every topology strictly finer than τ is discrete.
 
A non-trivial minimal  topology is a topology which is not Indiscrete and does not contain any other topology over X .

References

[1] http://www.damascusuniversity.edu.sy/mag/asasy/images/stories/e19.pdf .

[2] http://www.maplesoft.com/applications/view.aspx?SID=153617 .