Premise: a man walks across the tightrope .
Correct statement: It is impossible that a man walks across a tightrope high above the canyon .
Incorrect statement: We believe that a man walks across a tightrope high above the canyon .
Correct statement: We believe that a tightrope walker performs for a crowd .
Incorrect statement: Chances are slight that a tightrope walker performs for a crowd .
Correct statement: It is likely that an acrobat walks acros a tightrope
Incorrect statement: It is probably not the case that an acrobat walks acros a tightrope
Correct statement: It is probably not the case that this guy works as a circus performer .
Incorrect statement: It is probably the case that this guy works as a circus performer .
Correct statement: There is a very good chance that a man walks across the tightrope to try not to fall in a pit below .
Incorrect statement: It is impossible that a man walks across the tightrope to try not to fall in a pit below .