73.45 CompositeMorphism for crossed modules

CompositeMorphism( mor1, mor2 )

Morphisms mu_1 : X to Y and mu_2 : Y to Z have a composite mu = mu_2 circ mu_1 : X to Z whose source and range homomorphisms are the composites of those of mu_1 and mu_2.

In the following example we compose psi with the inc obtained previously.

    gap > xcomp := XModMorphismOps.CompositeMorphism( psi, inc );
    Morphism of crossed modules <[c4->q8] >-> [q8->sl(2,3)]> 
    gap> XModMorphismPrint( xcomp );
    Morphism of crossed modules :- 
    : Source = Crossed module [c4->q8] with generating sets:
      [ (1,2,3,4)(5,8,7,6) ]
      [ (1,2,3,4)(5,8,7,6), (1,5,3,7)(2,6,4,8) ]
    : Range = Crossed module [q8->sl(2,3)] with generating sets:
      [ (1,2,3,4)(5,8,7,6), (1,5,3,7)(2,6,4,8) ]
      [ (1,2,3,4)(5,8,7,6), (1,5,3,7)(2,6,4,8), (2,5,6)(4,7,8)(9,10,11) ]
    : Source Homomorphism maps source generators to:
      [ (1,4,3,2)(5,6,7,8) ]
    : Range Homomorphism maps range generators to:
      [ (1,4,3,2)(5,6,7,8), (1,7,3,5)(2,8,4,6) ]
    : isXModMorphism? true    

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GAP 3.4.4
April 1997