| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | system be to be | 40 |
|
| 2 | system [is] to be | 24 |
|
| 3 | system is to be | 24 |
|
| 4 | system [was/were] to be | 15 |
|
| 5 | system was to be | 11 |
|
