Premise: Two people signing books .
Correct statement: There is a very good chance that people are having a book signing in a bookstore .
Incorrect statement: We doubt that people are having a book signing in a bookstore .
Correct statement: There is a very good chance that two people in a bookstore .
Incorrect statement: Chances are slight that two people in a bookstore .
Correct statement: There is a very good chance that two authors are at a book signing .
Incorrect statement: It is impossible that two authors are at a book signing .
Correct statement: There is a very good chance that the people are famous .
Incorrect statement: It is highly unlikely that the people are famous .
Correct statement: Chances are about even that two people are at a library book signing event .
Incorrect statement: It is almost certain that two people are at a library book signing event .