// --------------
//  The G series
// --------------
height=400;
width =400;
clip=none;
clear_screen;
curve = (y+x+x*y)*x*y*(-(y+x+x*y)^3
        +4*(1+x+y)*(y+x+x*y)*x*y-8*x^2*y^2)
        *(256*(y+x+x*y)^4*x^4*y^4*(1+x+y)^4
        -1024*(1+x+y)^3*(y+x+x*y)^3*x^5*y^5
        -320*(1+x+y)^3*x^3*y^3*(y+x+x*y)^6
        +1792*(1+x+y)^2*x^6*y^6*(y+x+x*y)^2
        +896*(1+x+y)^2*x^4*y^4*(y+x+x*y)^5
        +160*(1+x+y)^2*x^2*y^2*(y+x+x*y)^8
        -1536*(y+x+x*y)*x^7*y^7*(1+x+y)
        -832*(y+x+x*y)^4*(1+x+y)*x^5*y^5
        -320*(1+x+y)*x^3*y^3*(y+x+x*y)^7
        -36*(1+x+y)*x*y*(y+x+x*y)^10
        +512*x^8*y^8+256*(y+x+x*y)^3*x^6*y^6
        +160*(y+x+x*y)^6*x^4*y^4
        +40*(y+x+x*y)^9*x^2*y^2+3*(y+x+x*y)^12);
epsilon=0.00001;
draw_curve;