Table 1 An example of incomplete ordered decision system.
From: Attribute reduction based on classes in incomplete ordered decision systems
U | \({a_1}\) | \({a_2}\) | \({a_3}\) | \({a_4}\) | d |
|---|---|---|---|---|---|
\({x_1}\) | 2 | 3 | 1 | 2 | 2 |
\({x_2}\) | 3 | 3 | 2 | 2 | 3 |
\({x_3}\) | 1 | 1 | * | 1 | 1 |
\({x_4}\) | 3 | 3 | 2 | * | 3 |
\({x_5}\) | 2 | 3 | 3 | 3 | 3 |
\({x_6}\) | 1 | 2 | 1 | * | 2 |
\({x_7}\) | 1 | 1 | * | 1 | 1 |
\({x_8}\) | * | 2 | * | 2 | 2 |
