CARAT Introduction / Programs / Zass_main

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## Program Zass_main

### Usage

    Zass_main 'file1' 'file2' ['file3'] ['file4'] [-s] [-c] [-d] [-t]

file1: matrix_TYP containing a presentation for G.
file2: bravais_TYP containing the unimodular group G.

### Description

Determines isomorphism type of the cohomology group H^1(G,Q^n/Z^n), or in slight abuse of notation (since for finite G they are isomorphic) the group of extensions H2(G,Qn/Zn).

### Options

    -s    : writes the system of equations nessecary to
          : determine the H^1(G,**) to file3
    -c    : writes the cocycles to file3.co or (or file4.co if
          : used together with -s) and the denomiantors to
          : file3.de (or file4.de respectively)
    -d    : writes a different output format, which is meant for
          : developing other programs, so do not us this option.
    -t    : give transformation matrix.

### Remarks

See also for Extensions/Vector_systems and Presentation.

### Examples

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