61.9 The DCE Universe

The various user functions described below operate on a record called a bf DCE Universe. This is created by the function DCESetup (or by DCE, which calls DCESetup) and is then passed as first argument to all other DCE functions. The following fields are likely to be of most interest:

K:

The group K. For brevity this group is given the name ``K''.

pres:

The presentation from which this universe was created.

isDCEUniverse:

Always true.

status:

A string describing the status of the enumeration. Values include:

``in end game'' -- The program believes that the enumeration is almost complete and has shifted to a Felsch-like strategy to try and finish it.

``early-closed'' -- The table is closed, that is has no blank entries, but the program has not actually proved that the permutation representation described satisfies all the relations. The program will stop under these circumstances if the degree falls within a range set by the user (see Strategies for Double Coset Enumeration

``running'' -- Enumeration is in progress.

``closed'' -- The enumeration has been completed.

``Setting up'' -- The data structures are still being initialized.

``Set up'' -- The data structures are initialized but computation has not yet started.

degree:

The number of single cosets represented by the current double coset table.

dcct:

The number of double cosets in the current table.

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