Yes / no, is the following a verifiable fact?
"Christopher Columbus explored a large portion of the world during the Age of Discovery."
Chain of thought and solution for this question is:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Christopher Columbus sailed from Western Europe to what we now know as North America in the late 15th Century.
So, the answer is yes.