gap> C:=PureComplexComplement(K);;
gap> C:=ContractedComplex(C);;
gap> G:=FundamentalGroup(C);;
gap> GeneratorsOfGroup(G);
[ f1, f2 ]
gap> RelatorsOfFpGroup(G);
[ f2*f1^-1*f2^-1*f1^-1*f2*f1 ]

gap> AlexanderPolynomial(G);
x_1^2-x_1+1
