[GAP Forum] The equivalence of the two methods to create finitely presented groups based on the quotient of a free group.

[Hongyi Zhao]

On Mon, May 2, 2022 at 6:38 PM Thomas Breuer <sam at math.rwth-aachen.de> wrote:
>
> Dear Hongyi,
>
> you wrote
>
> > 1. I try to query the built-in help with the following command, but
> > obtained so many entries I don't know how to choose from:
> >
> > gap> ?Comm
> >    Choose an entry to view, 'q' for none (or use ?<nr> later):
> >
> >          │
> > │[1]   Guarana (not loaded): Comm
> >
> >           │
> > │[2]   Utils: Comm
> >
> >           │
> > │[3]   ANUPQ (not loaded): Commands from the Main p-Quotient menu
> >                                                                 [...]
>
> In this situation, the GAP help system uses a pager
> that is apparently not as intuitive as it was intended.
> One entry is selected,
> you can move the selection up/down in the list of choices
> via the up/down arrow keys,
> and you can show the help for the selected entry by hitting the <Return> key.
> Entering 'q' takes you back to the GAP prompt.
>
> > 2. I also tried with the same method to check the following two commands:
> >
> > gap> ?quit
> > gap> ?QUIT
> >
> > Gap gives exactly the same document for them:
> >
> > > `quit'{quit}
> >     This  closes  all  windows and just brings you back to the GAP
> > window. In a new start of ITC all switches will be set to their
> > default values.
> >     The group that you had handled will still be available as a GAP object.
>
> This is a bit surprising.
> The text in question belongs to the help about 'quit'
> from the GAP package ITC;
> the list of choices should contain also entries for 'quit'
> from the GAP Tutorial and for 'QUIT' from the Reference Manual.

I rechecked as follows, but still can't see the stuff you mentioned above:

gap> ??quit
   Choose an entry to view, 'q' for none (or use ?<nr> later):                │
│[1]   ITC (not loaded): quit                                                  │
│[2]   ACE (not loaded): ACEQuit!introduction                                  │
│[3]   ACE (not loaded): ACEQuit!details                                       │
│[4]   ACE (not loaded): ACEQuit                                               │
│[5]   ACE (not loaded): ACEQuitAll                                            │
│[6]   ANUPQ (not loaded): PqQuit                                              │
│[7]   ANUPQ (not loaded): PqQuit for default process                          │
│[8]   ANUPQ (not loaded): PqQuitAll                                           │
│[9]   Browse: BrowseData.actions.QuitMode                                     │
│[10]  Browse: BrowseData.actions.QuitTable                                    │
│[11]  fwtree (not loaded): Obliquity                                          │
│[12]  fwtree (not loaded): HasObliquityZero                                   │
│[13]  fwtree (not loaded): GroupsByRankWidthObliquity

gap> ??QUIT
  Choose an entry to view, 'q' for none (or use ?<nr> later):                │
│[1]   ITC (not loaded): quit                                                  │
│[2]   ACE (not loaded): ACEQuit!introduction                                  │
│[3]   ACE (not loaded): ACEQuit!details                                       │
│[4]   ACE (not loaded): ACEQuit                                               │
│[5]   ACE (not loaded): ACEQuitAll                                            │
│[6]   ANUPQ (not loaded): PqQuit                                              │
│[7]   ANUPQ (not loaded): PqQuit for default process                          │
│[8]   ANUPQ (not loaded): PqQuitAll                                           │
│[9]   Browse: BrowseData.actions.QuitMode                                     │
│[10]  Browse: BrowseData.actions.QuitTable                                    │
│[11]  fwtree (not loaded): Obliquity                                          │
│[12]  fwtree (not loaded): HasObliquityZero                                   │
│[13]  fwtree (not loaded): GroupsByRankWidthObliquity                         │
│

> All the best
> Thomas

Yours,
Hongsheng