Here, I'll do you the favor of giving you a few more Google
results with hopes that you'll start developing a mental model
behind what the definition of assertion is:
Google itself: "state a fact or belief confidently and forcefully"
http://dictionary.reference.com/browse/assert: "to state with
assurance, confidence, or force; state strongly or positively;
affirm"
http://www.merriam-webster.com/dictionary/assert: "to state
(something) in a strong and definite way"
http://www.thefreedictionary.com/assert: "To state or express
positively; affirm"
http://www.oxforddictionaries.com/us/definition/american_english/assert:
"State a fact or belief confidently and forcefully"
http://www.macmillandictionary.com/us/dictionary/american/assert:
"to state firmly that something is true"
As a bonus, Googling "statement of fact" in case that isn't clear
to you what that means (maybe that's what's throwing you for a
loop? You seem to be equating statement of fact and facts so
you've clearly got some understanding wrong for the definition of
those two):
http://en.wikipedia.org/wiki/False_statements_of_fact
False statement of fact... You can't possibly suggest that there
exists false facts, but false statements of facts do exist,
proving that statement of fact != fact.
