Premise: Two workers , working on a rooftop , looking over a town .
Correct statement: It is certain that some workers look at a town
Incorrect statement: It is unlikely that some workers look at a town
Correct statement: It is likely that two workers are taking a break .
Incorrect statement: It is impossible that two workers are taking a break .
Correct statement: It is likely that the workers are men .
Incorrect statement: It is impossible that the workers are men .
Correct statement: We believe that workers are repairing a roof .
Incorrect statement: It is impossible that workers are repairing a roof .
Correct statement: We doubt that tall people on a roof
Incorrect statement: We believe that tall people on a roof