What do you mean by 'knowledge artifacts'?
I tested your bot, and the AIML scripts you added seem to be working.
You: who invented the light bulb
Xecta V2: Thomas Edison invented .
You: what did hal do?
Xecta V2: He had a few issues to work out.
You can import AIML scripts from two places. When adding from the Program page, it will be added as a script, and the list of scripts will be executed in the order of the list. So something from a script higher up in the list can take precedence.
You can also import AIML scripts from the Chat Logs page. The script will not be executed as a script, but the patterns/templates will be added to the bots known responses, and the bot will decide when to use them.