Read it somewhere, can't recall where. It ought to be covered in writing along the lines of: https://plato.stanford.edu/entries/knowledge-analysis/
EDIT: What number of facts do you believe would be necessary to understand an encyclopedia article using no other references? Please note that the article did mention that many of these were logical conclusions such as a child must be younger than a parent.
As an example of how difficult encoding information for A.I., a recent game tried to use A.I. agents for all the characters in the game --- when they first started one up, the in-game avatar simply stayed in place and looked at itself --- when they debugged the code they determined that it had determined it was in need of food, had identified its own body as the nearest foodsource and was trying to figure out how to eat itself.
Consider the recent instance of teaching a computer to play Go --- they simply had it play a copy of itself untold millions of times --- it worked, and created a program which could beat every other program in existence, but the game play style was unusual, and that's not a technique which can be used for other problems.