i1 : C = PP_(ZZ/100003)^(1,4);
o1 : ProjectiveVariety, curve in PP^4

i2 : L = linearSpan sum{point C,point C}, L' = linearSpan sum{point C,point ambient C};

i3 : X = ⋃ {C,L,L'};
o3 : ProjectiveVariety, curve in PP^4

i4 : D = decompose X
o4 = {curve in PP^4 cut out by 3 hypersurfaces of degree 1, curve in PP^4 cut

out by 3 hypersurfaces of degree 1, curve in PP^4 cut out by 6

hypersurfaces of degree 2}
o4 : List

i5 : assert(X == ⋃ D)
