73.30 IsXModMorphism

IsXModMorphism( mor )

This Boolean function checks that mor includes homomorphisms between the corresponding source and range crossed modules, and that these homomorphisms commute with the two actions. In the example we increase the value of XModPrintLevel to show the effect of such an increase in a simple case.

    gap> XModPrintLevel := 3;;
    gap> IsXModMorphism( mor );
    Checking that the diagram commutes :- 
             Y.boundary(morsrc(x)) = morrng(X.boundary(x)) 
    Checking:  morsrc(x2^x1) = morsrc(x2)^(morrng(x1))
    true
    gap> XModPrintLevel := 1;;   

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