In formal analogies, : is pronounced "is to" and :: is pronounced "as".

The purpose here is to use the relationship from a known, to describe the relationship between a partial known.

ChatGPT is to GPT3 as ChatLLaMa is to LLaMa. It uses the relationship between ChatGPT and GPT3 to extrapolate a relationship between an unknown and LLaMa.

see Analogies.pdf https://resources.finalsite.net/images/v1584287027/brockton/...

Corolla:Toyota::3-Series:BMW. If you had heard of a Corolla, Toyota, and BMW, but not a 3-Series, you now roughly know that a 3-Series is BMWs equivalent to a Corolla.