### Is it possible to edit the content of an expression by hand?

Hi,

Is it possible to edit an expression by hand? I know some terms in my calculation ~~is ~~are not important and want to delete them by hand before the next step. However, I didn't find a way to do that.

To be explicit, is there a function to print the sage output in terms of an input form (like the Mathematica InputForm[] function), so I can edit and evaluate it again? For example,

```
sage: f = function('f', var('t'))
sage: expand((diff(f,t)+1)**2)
D[0](f)(t)^2 + 2*D[0](f)(t) + 1
```

I want to delete the "+1" in the output and save the "D[0](f)(t)^2 + 2*D[0](f)(t)" in another variable. Is it possible to do that? Directly write

```
g = D[0](f)(t)^2 + 2*D[0](f)(t)
```

doesn't make sense. Sage says 'D' is not defined.