| carb | 7 | degree |
| in order to begin work | 4 | purpose |
| in underground mining environments | 3 | location |
| engine → be → certified | 40 |
| engine → be certified in → accordance | 3 |
| engine → be certified for → use | 3 |
| engine → be certified by → ce | 3 |
| negative | neutral | positive |
| 0.131 | 0.572 | 0.297 |
| Raw frequency | 49 |
| Normalized frequency | 0.452 |
| Modifier score | 0.500 |
| Perplexity | 421.688 |