Maximal, greatest, minimal and least elements of a set

[Vishera]

Definition of maximal, greatest, minimal and least elements of a set: http://i.stack.imgur.com/PnI9V.png

Since c is a minimal element but c is not a least element, this implies that there is one element that is not comparable to c. What is that element? What about d and i?

 

[micromass]

The elements $d$, $i$, $e$, $f$ and $h$ are not comparable to $c$.