sympy/sympy — pull request #686 by smichr (2011-10-28 12:13:42+00:00)
Title: 2758: sqrtdenest needs to check if a match pattern was obtained

In addition, subexpressions are tested so the input expression
no longer need be a sqrt.

http://code.google.com/p/sympy/issues/detail?id=2758

```python
>>> pprint(sqrt(1/(4*sqrt(3) + 7) + 1)+1)
_________________
/ 1
1 + / ----------- + 1
/ ___
\/ 4*\/ 3 + 7
>>> pprint(sqrtdenest(sqrt(1/(4*sqrt(3) + 7) + 1)+1))
___ ___
\/ 2 + \/ 6
1 + -------------
___
\/ 3 + 2
```