GAP Manual: 3.6. Reading Sections

If the section is longer than 24 lines GAP stops after 24 lines and displays

    -- <space> for more --

If you press space GAP displays the next 24 lines of the section and then stops again. This goes on until the whole section has been displayed, at which point GAP will return immediately to the main GAP loop. Pressing f has the same effect as space.

You can also press b or the key labeled del which will scroll back to the previous 24 lines of the section. If you press b or del when GAP is displaying the top of a section GAP will ring the bell.

You can also press q to quit and return immediately back to the main GAP loop without reading the rest of the section.

Actually the 24 is only a default, if you have a larger screen that can display more lines of text you may want to tell this to GAP with the -y rows option when you start GAP.