mkinc man page

mkinc — compute mountains and incidence matrix of a module


mkinc [Options] <Name>


This program runs in two steps.  During the first step, all cyclic submodules found by mkcycl(1) are uncondensed, giving the local submodules, the "mountains", of the original module.  Then, each local submodule is projected back to the condensed module, and all cyclic vectors which are contained in the image are found.  At the end of this step, there is a list of local submodules and, for each local submodule, a list of cyclic subspaces in the condensed module.  This information is written to Name.mnt.

In the second step, mkinc computes the incidence relation between local submodules.  The result is a matrix which contains a 1 for each incidence. This matrix is written to the file



Quiet, no messages.


Verbose, more messages.

-T <MaxTime>

Set CPU time limit


Produce output in GAP format.  This option implies -Q.

Implementation Details

The whole calculation of step 2 is done in the condensed modules.  This is possible because incidences between local submodules do not change if they are condensed.  Usually this saves a lot of both memory and CPU time because one does not have to keep all mountains simultaneously, and the condensed modules have a smaller dimension.

Input Files


Constituent info file.


Generators on the constituents.


Generators on the condensed modules.


Cyclic submodules, generated by mkcycl(1).


Images used for condensation.


Uncondense matrices.

Output Files


Constituent info file.




Mountain dimensions and classes of cyclic submodules corresponding to the mountains.

Incidence matrix.

See Also

mkcycl(1), mkdotl(1)

Referenced By

genmod(1), mkdotl(1), mksub(1).

2.4.24 MeatAxe User Commands