### extracting info from diff_map definition

I've defined the following diff_map

```
R2 = Manifold(2, 'R2', start_index=1, latex_name=r'\mathbb{R}^2')
cartesian2d.<x, y> = R2.chart()
R1 = Manifold(1, 'R1', start_index=1, latex_name=r'\mathbb{R}^1')
cartesian1d.<t> = R1.chart()
h = R1.diff_map(R2, [1-t, sqrt(2*t-t^2)])
h.display()
```

I would like to extract the elements of the diff_map, namely `1-t`

and `sqrt(2*t-t^2)`

for propose of plotting the resulting curve or for other manipulations. How can I do that?

Thanks,

Daniel