For each of the following sets of statements, ascertain whether X and Y are compatible.
| X | Y | compatible? | |
| 1 | 2 + 2 = 4 | The sky is blue. | |
| 2 | 2 + 2 = 5 | Topeka is the capital of Kansas. | |
| 3 | Bob Dole is the president. | Dick Cheney is the president. | |
| 4 | Bob Dole has been president. | Dick Cheney has been president. | |
| 5 | Today is Monday. | Today is not Monday. (said on the same day) | |
| 6 | Today is Monday. | Today is not Monday. (said on a different day) | |
| 7 | Lying is wrong. | Lying is not wrong. | |
| 8 | I believe lying is wrong. | I believe lying is not wrong. (said by a different person) | |
| 9 | I disapprove of lying. | I do not disapprove of lying. (said by a different person) |