When you do symbolic calculations, it is quite easy to end up with extremely complicated expressions. Often, you will not even want to see the complete result of a computation.
If you end your input with a semicolon, the Wolfram Language will do the computation you asked for, but will not display the result. You can nevertheless use % or Out[n] to refer to the result.
By default, the Wolfram System front end will display any outputs which are excessively large in a shortened form inside an interface which allows you to refine the display of the output.
The Wolfram System shows this output with 5138 of the terms omitted.
The Show Less and Show More buttons allow you to decrease or increase the level of detail to which the Wolfram System shows the expression. The Show Full Output button removes the interface entirely and displays the full result, but the result may take considerable time to display. The default threshold size at which this feature starts working may be set using the Set Size Limit option, which opens the Preferences dialog to the panel with the appropriate setting.
The large output suppression feature is implemented using the Wolfram Language function Short. You can use Short directly for finer control over the display of expressions. You can also use it for outputs that are not large enough to be suppressed by the default suppression scheme.
Ending your input with ; stops the Wolfram Language from displaying the complicated result of the computation.
You can still refer to the result as %. //Short displays a one‐line outline of the result. The <<n>> stands for n terms that have been left out.
This shows a three‐line version of the expression. More parts are now visible.