sympy/sympy — pull request #1251 by mrocklin (2012-04-19 12:12:07+00:00)
Title: Latex Printing of TransformationSet

Now we latex print TransformationSets in the form

```python
In [1]: print latex(TransformationSet(Lambda(x, x**2), S.Naturals))
\left\{x^{2}\; |\; x \in \mathbb{N}\right\}
```

looks like {x^2 | x \in N}

Or for multiple variables in the base set

```python
In [4]: r, th = symbols('r, theta', real=True)
In [5]: L = Lambda((r, th), (r*cos(th), r*sin(th)))
In [6]: halfcircle = TransformationSet(L, Interval(0, 1)*Interval(0, pi))
In [7]: print latex(halfcircle)
```
looks like
http://goo.gl/nSZb3

Also fixed ProductSet to use \times rather than \cross (which doesn't seem to exist)