Question: Yes / no, is the following a verifiable fact?
"Many people cook Hamburgers on a grill during the fourth of July."

Let me think..... The fourth of July is a popular grilling holiday and hamburgers can be cooked on a grill. The answer is yes.

Question: Yes / no, is the following a verifiable fact?
"Umpire makes decisions about balls and strikes."

Let me think..... Umpire (baseball) is the chief official doing this. The answer is yes.

Question: Is the following statement true?
"Linköping, named after the Lionga ting assembly, per Medieval Scandinavian laws was the most important thing in Östergötland."

Let me think..... Exact location of the Lionga ting is not known, but it was along the Eriksgata, Sweden. The answer is yes.

Question: Is the following sentence factually correct?
"Leonardo da Vinci invented many machines that are still relevant today."
Options:
- yes
- no
Let me think..... Leonardo da Vinci's inventions are ahead of his time. The answer is yes.