N:=100; A:=NullMat(N,N);; A:=List([1..N],i->StructuralCopy(A));; A[Int(N/2)][Int(N/2)][Int(N/2)]:=1; M:=PureCubicalComplex(A*0);; B2:=PureCubicalComplex(A); for i in [1..Int(N/2)-1] do B1:=B2; B2:=ThickenedPureComplex(B1); S:=PureComplexDifference(B2,B1); if IsOddInt(i) then M:=PureComplexUnion(M,S); fi; od; for i in [2..Int(N/2)-1] do M!.binaryArray[Int(N/2)][Int(N/2)][i]:=1; od;