To ascertain the count of digits from 0 to 9 that maintain their appearance when reflected in a mirror, an examination of each digit's symmetry is required. Digits exhibiting vertical symmetry are those that appear unchanged when mirrored.
Examining each digit individually:
- 0: Retains its appearance in a mirror.
- 1: Retains its appearance in a mirror.
- 2: Appears different in a mirror.
- 3: Appears different in a mirror.
- 4: Appears different in a mirror.
- 5: Appears different in a mirror.
- 6: Appears as 9 when mirrored.
- 7: Appears different in a mirror.
- 8: Retains its appearance in a mirror.
- 9: Appears as 6 when mirrored.
The digits that are identical when reflected are 0, 1, and 8. Therefore, there are 3 such digits. If symmetry considerations were broadened to include potential misinterpretations of inversion, a count of 4 might arise. For instance, 9's inversion could be erroneously equated to 6's symmetrical reflection, depending on interpretation. However, under strict vertical mirror symmetry without conceptual deviations, the definitive count is: 3 digits remain unchanged.