Lambdas Scope

[Salih Dincer via Digitalmars-d-learn]

How is this possible? Why is it compiled? Don't the same names in 
the same scope conflict?

```d
int function(int) square;
void main()
{
  square = (int a) => a * a;
  int square = 5.square;
  assert(square == 25);
}
```
Thanks, SDB@79