gap-packages / polycyclic

Computation with polycyclic groups
https://gap-packages.github.io/polycyclic/
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NormalIntersection runs forever on certain subgroups #76

Open stertooy opened 2 years ago

stertooy commented 2 years ago
gap> G := ExamplesOfSomePcpGroups( 8 );
gap> T := Subgroup( G, [ G.1^3*G.2^6*G.3^2*G.5^44, G.2^12*G.3*G.5^61, G.3^3*G.5^30, G.4^3*G.5^30, G.5^162 ] );
gap> K := Subgroup( G, [ G.1^3*G.2^6*G.5^3, G.2^12, G.3*G.5^7, G.4^3*G.5^3, G.5^9 ] );
gap> IsNormal( K, T );
true
gap> IsNormal( T, K );
true
gap> IsSubgroup( K, T );
true
gap> Index( K, T );
54
gap> NormalIntersection( T, K );
Pcp-group with orders [ 0, 0, 0, 0, 0 ]
gap> NormalIntersection( K, T );
[ this runs forever ]