I'm not sure I'm being dumb but are these all actual lattices (formally speaking) as the division examples don't have (at least not explicitly) a LUB for {4, 6, 10}.
Yes and this is not the only error in the article. I'm not even sure what this is supposed to mean:
""" Every operation which preserves a lattice and doesn't use "incomparable" objects is equivalent to addition. """
And the statement at the end: "any lattice is equivalent to another lattice where the relationship is set inclusion." This only holds for distributive lattices.
For another take on lattice theory, and ordered structures more generally:
