You will notice that each time you search for a keyword, the resulting set of records is assigned a number. You can use these numbers to re-use previous sets and form a new one. In the example below, the results of set 4 AND 8 were combined to form a new set (9). Similarly, you could a add new terms to an existing search set.
| No. | Records | Search |
|---|---|---|
| #1 | 1173 | PEAR |
| #2 | 1327 | PEARS |
| #3 | 1316 | PYRUS |
| #4 | 1650 | PEAR or PEARS or PYRUS |
| #5 | 152 | CCC |
| #6 | 84 | CYCOCEL |
| #7 | 278 | CHLORMEQUAT |
| #8 | 316 | CCC or CYCOCEL or CHLORMEQUAT |
| #9 | 4 | #4 and #8 |
N.B.This is an accurate and safe way to construct longer searches.