------
## 最终结论
```python
import re

def text_match_two_three(text):
    pattern = r'ab{2,3}'
    if re.search(pattern, text):
        return 'Found a match!'
    else:
        return 'Not matched!'

# Test cases
assert text_match_two_three("ac") == ('Not matched!')
assert text_match_two_three("dc") == ('Not matched!')
assert text_match_two_three("abbbba") == ('Found a match!')
```