Premise: two guys in street cloths doing some marshal arts .
Correct statement: We believe that two men perform martial arts as part of a defense class .
Incorrect statement: It is improbable that two men perform martial arts as part of a defense class .
Correct statement: We believe that a couple of guys challenge each other to marshal arts in their street clothes .
Incorrect statement: It is highly unlikely that a couple of guys challenge each other to marshal arts in their street clothes .
Correct statement: There is a very good chance that two men are practicing martial arts .
Incorrect statement: It is unlikely that two men are practicing martial arts .
Correct statement: It is impossible that there are two men in street clothes doing Jujitsu in the park .
Incorrect statement: There is a better than even chance that there are two men in street clothes doing Jujitsu in the park .
Correct statement: Chances are about even that two guys are in white street clothes .
Incorrect statement: It is almost certain that two guys are in white street clothes .