| Answer | Crossword Clue |
|---|---|
| EULER | Pioneer in graph theory |
| EULER | 18th-century pioneer in graph theory |
| EULER | Graph theory pioneer |
| EULER | Swiss who pioneered in graph theory |
| NODE | Either end of an edge, in graph theory |
| combinatorics | The branch of mathematics dealing with combinations of objects belonging to a finite set in accordance with certain constraints, such as those of graph theory |
| COPERNICUS | Pioneer in heliocentric theory |
| EULER | Pioneer in number theory |
| ALBERTEINSTEIN | Pioneer in quantum theory |
| BOHR | Pioneer in quantum theory |
| LAPLACE | French pioneer in planetary orbital theory |
| ALBERTEINSTEIN | 20th cen. pioneer in mathematical theory. |
