Mathematical commands are typed after the prompt >. A command is not complete until it ends with a semicolon ; or a colon : (followed by pressing the Enter key, of course). Therefore, very long commands may be typed on multiple lines with no action taken until the ending ; or :. A semicolon means show the output, while a terminating colon means suppress the output of the command. The colon is useful for commands that produce a lot of output of no particular importance.