Читать книгу Computer Aided Design and Manufacturing - Zhuming Bi - Страница 56
Example 2.6
ОглавлениеTo use the Euler–Poincare Law to justify the validity of open objects in the first column of Table 2.8.
Table 2.8 Examples of open objects.
| Example | F | E | V | L | B | G | F − E + V − L = B − G |
| 0 | 1 | 2 | 0 | 1 | 0 | 0 − 1 + 2–0 ≡ 1 − 0 | |
| 0 | 3 | 4 | 0 | 1 | 0 | 0 − 3 + 4 − 0 ≡ 1 − 0 | |
| 2 | 8 | 8 | 1 | 1 | 0 | 2 − 8 + 8 − 1 ≡ 1 − 0 | |
| 2 | 2 | 2 | 1 | 1 | 0 | 2 − 2 + 2 − 1 ≡ 1 − 0 | |
| 1 | 4 | 4 | 0 | 1 | 0 | 1 − 4 + 4 − 0 ≡ 1 − 0 | |
| 5 | 12 | 8 | 0 | 1 | 0 | 5 − 12 + 8 − 0 ≡ 1 − 0 |
