## P1xP1 as polytope ## gapcolor ## gap> LoadPackage( "ToricVarieties" ); true gap> P1P1 := Polytope( [[1,1],[1,-1],[-1,-1],[-1,1]] ); gap> P1P1 := ToricVariety( P1P1 ); gap> IsProjective( P1P1 ); true gap> IsComplete( P1P1 ); true gap> CoordinateRingOfTorus( P1P1, "x" ); Q[x1,x1_,x2,x2_]/( x2*x2_-1, x1*x1_-1 ) gap> IsVeryAmple( Polytope( P1P1 ) ); true gap> ProjectiveEmbedding( P1P1 ); [ |[ x1_*x2_ ]|, |[ x1_ ]|, |[ x1_*x2 ]|, |[ x2_ ]|, |[ 1 ]|, |[ x2 ]|, |[ x1*x2_ ]|, |[ x1 ]|, |[ x1*x2 ]| ] gap> Length( last ); 9 ## endgapcolor ##