  |         |          |                  |          |
| f_0  | f_0000 | 0 0 0 0 |    ()    | false            |    0     |
|      |        |         |          |                  |          |
| f_1  | f_0001 | 0 0 0 1 |  (p)(q)  | neither p nor q  | ~p &amp; ~q  |
|      |        |         |          |                  |          |
| f_2  | f_0010 | 0 0 1 0 |  (p) q   | q and not p      | ~p &amp;  q  |
|      |        |         |          |                  |          |
| f_3  | f_0011 | 0 0 1 1 |  (p)   