### Does Sage have a plain math expression editor, without any calculation performed?

Is there a way to edit an expression in a pretty, classical, math style without declaring variables and without evaluating?

In Mathematica we can write whatever we want using some keystroke shortcuts and it looks just as if it were hand-written. We can keep these notes in a file and re-use them (visualize, modify...) later on. The powerful feature is that we can copy and paste any part of such notes into a notebook and get it evaluated in the most straightforward way.

Can we do this in Sage?