This question already has an answer here:
I know that a chain is always a lattice (https://math.stackexchange.com/questions/974596/is-every-chain-a-lattice#=), where
- A chain is a subset of a poset in which every two elements are comparable and
- A lattice is a poset in which every finite subset has a greatest lower bound and a lowest upper bound.
What would be an example of a lattice that isn't a chain? Or are they equivalent?