Halliday & Matthiessen (2014: 615):
In this type of elaboration some element is re-presented, or restated, either (i) by exposition, the ‘i.e.’ relation, or (ii) by example, the ‘e.g.’ relation.(i) expository:
I guess the main editorial rule that we work by is to treat all manuscripts equally. I mean, it doesn’t make any difference who the author is.
(ii) exemplifying:
Our humour is founded on very close observation, very, very close observation of reality. You find some humorous proverbs, for instance, and the humour is that whoever made these proverbs was not going around the world with his eyes closed. For example, the dog says that those who have buttocks do not know how to sit.