Proving me ? partial orders :hasse diagrams

[rami070]

partial orders :hasse diagrams
theorem : if [A,R] is poset and A is finite , then A has both a maximal and a minimal element

A={a1,a2,a3...an}

but i know prove it is maximal , but i not know how i prove it is minimal ?




please answer ?

 

[micromass]

How did you prove that there is a maximal element?

 

[rami070]

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s320x320/400327_199078300188664_100002594878940_372880_1793624919_n.jpg

 

[rami070]

see it i prove

 

[rami070]

see it is proved