Hi,

I have this problem:

Show that there is exactly one greatest element of a poset, if such element exists.

I dont know if my proof is rigth:

Suppose that there are 2 greatest elements a and b in the poset(P,R).

thus, a R b and b R a -->a=b ( antisymetric). so it is unique.

Can someone someone correct me if I am wrong?

B.