Type41-50.mws

> read `/Documents and Settings/ibuki/My Documents/ESC/ESC.mpl`;
ESC();
 

`Elliptic Surface Calculator v.1.01. c.1990-2008` (1)
 

> with(algcurves):
 

TypeNo.41 

> qc[41]:=x^4+y^4-y^2*z^2-x^3*z;
 

`:=`(qc[41], `+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(`^`(y, 2), `*`(`^`(z, 2)))), `-`(`*`(`^`(x, 3), `*`(z))))) (1.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[41]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[41]),x,y);
 

{[[0, 0, 1], 2, 1, 1]} (1.2)
 

> subs(z=t*x,qc[41]);
 

`+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(`^`(y, 2), `*`(`^`(t, 2), `*`(`^`(x, 2))))), `-`(`*`(`^`(x, 4), `*`(t)))) (1.3)
 

> Q41:=mapfactor(subs({y=1,x=U},%),U);
 

`:=`(Q41, `+`(`-`(`*`(`^`(t, 2), `*`(`^`(U, 2)))), `-`(`*`(`+`(`-`(1), t), `*`(`^`(U, 4)))), 1)) (1.4)
 

> subs(U=0,Q41);
simplify(%);
 

1 (1.5)
 

1 (1.5)
 

> Quartic_to_Weierstrass(Q41,[0,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `-`(`*`(`+`(`-`(4), `*`(4, `*`(t))), `*`(X, `*`(`^`(Z, 2))))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `-`(`*`(`+`(`-`(4), `*`(4, `*`(t))), `*`(X, `*`(`^`(Z, 2))))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `-`(`*`(`+`(`-`(4), `*`(4, `*`(t))), `*`(X, `*`(`^`(Z, 2))))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^...
(1.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(`+`(`-`(1), t), `*`(X, `*`(`^`(Z, 2)))))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^`(Z, ...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(`+`(`-`(1), t), `*`(X, `*`(`^`(Z, 2)))))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^`(Z, ...
(1.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(`+`(`-`(1), t), `*`(X, `*`(`^`(Z, 2)))))), `*`(`^`(t, 2), `*`(`^`(X, 2), `*`(Z))), `*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t), `*`(`^`(Z, ... (1.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (1.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `-`(`*`(`^`(t, 2), `*`(`^`(x, 2)))), `*`(`+`(`-`(4), `*`(4, `*`(t))), `*`(x)), `-`(`*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t)))))) (1.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `-`(`*`(`^`(t, 2), `*`(`^`(x, 2)))), `*`(`+`(`-`(4), `*`(4, `*`(t))), `*`(x)), `-`(`*`(4, `*`(`^`(t, 2), `*`(`+`(`-`(1), t)))))) (1.10)
 

Discriminant = `+`(`-`(`*`(256, `*`(`+`(`-`(1), t), `*`(`^`(`+`(`*`(`^`(t, 4)), `*`(4, `*`(t)), `-`(4)), 2)))))) (1.10)
 

`+`(jay, `-`(invariant)) = `+`(`-`(`/`(`*`(16, `*`(`^`(`+`(`*`(`^`(t, 4)), 12, `-`(`*`(12, `*`(t)))), 3))), `*`(`+`(`-`(1), t), `*`(`^`(`+`(`*`(`^`(t, 4)), `*`(4, `*`(t)), `-`(4)), 2)))))) (1.10)
 

`
` (1.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.41. (1.10)
 

`
` (1.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (1.10)
 

`
` (1.10)
 

The rank of the Mordell-Weil group over C is 2. (1.10)
 

` ` (1.10)
 

latex(y^2 = x^3-t^2*x^2+(-4+4*t)*x-4*t^2*(-1+t)); 

{y}^{2}={x}^{3}-{t}^{2}{x}^{2}+ \left( -4+4\,t \right) x-4\,{t}^{2}
 

\left( t-1 \right)
 

>
 

TypeNo.42 

> qc[42]:=(z^2+x^2+6*x*y-4*y^2)^2-12*x*y*(x-y)*(x+4*y);
 

`:=`(qc[42], `+`(`*`(`^`(`+`(`*`(`^`(z, 2)), `*`(`^`(x, 2)), `*`(6, `*`(x, `*`(y))), `-`(`*`(4, `*`(`^`(y, 2))))), 2)), `-`(`*`(12, `*`(x, `*`(y, `*`(`+`(x, `-`(y)), `*`(`+`(x, `*`(4, `*`(y))))))))))) (2.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[42]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[42]),x,y);
 

{[[-2, 1, 0], 2, 1, 2], [[2, 1, 0], 2, 1, 2]} (2.2)
 

> subs(y=t*x,qc[42]);
 

`+`(`*`(`^`(`+`(`*`(`^`(z, 2)), `*`(`^`(x, 2)), `*`(6, `*`(`^`(x, 2), `*`(t))), `-`(`*`(4, `*`(`^`(t, 2), `*`(`^`(x, 2)))))), 2)), `-`(`*`(12, `*`(`^`(x, 2), `*`(t, `*`(`+`(x, `-`(`*`(t, `*`(x)))), `*... (2.3)
 

> Q42:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q42, `+`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), `*`(`^`(U, 4)))), `-`(`*`(2, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `-`(1), `-`(`*`(6, `*`(t)))), `*`(`^`(U, 2))))),... (2.4)
 

> subs(U=0,Q42);
simplify(%);
 

1 (2.5)
 

1 (2.5)
 

> Quartic_to_Weierstrass(Q42,[0,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(X, 2), `*`(Z)))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(X, 2), `*`(Z)))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(X, 2), `*`(Z)))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(X, 2), `*`(Z)))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(X, 2), `*`(Z)))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`...
(2.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(2, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `-`(1), `-`(`*`(6, `*`(t)))), `*`(`^`(X, 2), `*`(Z)))), `*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(...
`+`(`*`(2, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `-`(1), `-`(`*`(6, `*`(t)))), `*`(`^`(X, 2), `*`(Z)))), `*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(...
(2.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(2, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `-`(1), `-`(`*`(6, `*`(t)))), `*`(`^`(X, 2), `*`(Z)))), `*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(...
`+`(`*`(2, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `-`(1), `-`(`*`(6, `*`(t)))), `*`(`^`(X, 2), `*`(Z)))), `*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(...
(2.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (2.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(x, 2))), `-`(`*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), ...
`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(x, 2))), `-`(`*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), ...
(2.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(x, 2))), `-`(`*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), ...
`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(8, `*`(`^`(t, 2)))), 2, `*`(12, `*`(t))), `*`(`^`(x, 2))), `-`(`*`(4, `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), ...
(2.10)
 

Discriminant = `+`(`*`(589824, `*`(`^`(t, 2), `*`(`^`(`+`(t, `-`(1)), 2), `*`(`^`(`+`(`*`(2, `*`(t)), 1), 2), `*`(`^`(`+`(`*`(2, `*`(t)), `-`(1)), 2), `*`(`^`(`+`(`*`(4, `*`(t)), 1), 2)))))))) (2.10)
 

`+`(jay, `-`(invariant)) = `+`(`/`(`*`(256, `*`(`^`(`+`(1, `*`(`^`(t, 2)), `*`(3, `*`(t)), `*`(16, `*`(`^`(t, 4))), `-`(`*`(12, `*`(`^`(t, 3))))), 3))), `*`(9, `*`(`^`(t, 2), `*`(`^`(`+`(t, `-`(1)), 2... (2.10)
 

`
` (2.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.42. (2.10)
 

`
` (2.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (2.10)
 

`
` (2.10)
 

The rank of the Mordell-Weil group over C is 2. (2.10)
 

` ` (2.10)
 

>
 

Type No. 43 

> qc[43]:=x^4-y^3*z;
 

`:=`(qc[43], `+`(`*`(`^`(x, 4)), `-`(`*`(`^`(y, 3), `*`(z))))) (3.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[43]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[43]),x,y);
 

{[[0, 0, 1], 3, 3, 1]} (3.2)
 

> subs(y=t*(x-z),qc[43]);
 

`+`(`*`(`^`(x, 4)), `-`(`*`(`^`(t, 3), `*`(`^`(`+`(x, `-`(z)), 3), `*`(z))))) (3.3)
 

> Q43:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q43, `+`(`*`(`^`(U, 4)), `-`(`*`(`^`(t, 3), `*`(`^`(U, 3)))), `*`(3, `*`(`^`(t, 3), `*`(`^`(U, 2)))), `-`(`*`(3, `*`(`^`(t, 3), `*`(U)))), `*`(`^`(t, 3)))) (3.4)
 

> subs(U=1,Q43);
simplify(%);
 

1 (3.5)
 

1 (3.5)
 

> Quartic_to_Weierstrass(Q43,[1,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 3)))), 8), `*`(Y, `*`(`^`(Z, 2)))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `-`(`*`(2, `*`(`^`(X, 2), `*`(Z)))), `*`(8, `*`(`^`(Z...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 3)))), 8), `*`(Y, `*`(`^`(Z, 2)))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `-`(`*`(2, `*`(`^`(X, 2), `*`(Z)))), `*`(8, `*`(`^`(Z...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 3)))), 8), `*`(Y, `*`(`^`(Z, 2)))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `-`(`*`(2, `*`(`^`(X, 2), `*`(Z)))), `*`(8, `*`(`^`(Z...
(3.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`+`(`*`(`^`(t, 3)), `-`(3)), `*`(X, `*`(`^`(Z, 2))))), `-`(`*`(6, `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 3)))), `*`(`^`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`+`(`*`(`^`(t, 3)), `-`(3)), `*`(X, `*`(`^`(Z, 2))))), `-`(`*`(6, `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 3)))), `*`(`^`...
(3.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(4, `*`(`+`(`*`(`^`(t, 3)), `-`(3)), `*`(X, `*`(`^`(Z, 2))))), `-`(`*`(6, `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(`-`(`*`(8, `*`(`^`(t, 3)))), `*`(`^`... (3.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (3.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(6, `*`(`^`(x, 2))), `*`(`+`(`-`(`*`(4, `*`(`^`(t, 3)))), 12), `*`(x)), `-`(`*`(8, `*`(`^`(t, 3)))), `*`(`^`(t, 6)), 8) (3.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(6, `*`(`^`(x, 2))), `*`(`+`(`-`(`*`(4, `*`(`^`(t, 3)))), 12), `*`(x)), `-`(`*`(8, `*`(`^`(t, 3)))), `*`(`^`(t, 6)), 8) (3.10)
 

Discriminant = `+`(`-`(`*`(16, `*`(`^`(t, 9), `*`(`+`(`-`(256), `*`(27, `*`(`^`(t, 3))))))))) (3.10)
 

`+`(jay, `-`(invariant)) = `+`(`-`(`/`(`*`(442368), `*`(`+`(`-`(256), `*`(27, `*`(`^`(t, 3)))))))) (3.10)
 

`
` (3.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.43. (3.10)
 

`
` (3.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (3.10)
 

`
` (3.10)
 

The rank of the Mordell-Weil group over C is 1. (3.10)
 

` ` (3.10)
 

>
 

TypeNo.44 

> qc[44]:=(x^2-y*z)*(x^2+y*z);
 

`:=`(qc[44], `*`(`+`(`*`(`^`(x, 2)), `-`(`*`(y, `*`(z)))), `*`(`+`(`*`(`^`(x, 2)), `*`(y, `*`(z)))))) (4.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[44]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[44]),x,y);
 

{[[0, 0, 1], 2, 2, 2], [[0, 1, 0], 2, 2, 2]} (4.2)
 

> subs(y=t*x+z,qc[44]);
 

`*`(`+`(`*`(`^`(x, 2)), `-`(`*`(`+`(`*`(t, `*`(x)), z), `*`(z)))), `*`(`+`(`*`(`^`(x, 2)), `*`(`+`(`*`(t, `*`(x)), z), `*`(z))))) (4.3)
 

> Q44:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q44, `+`(`*`(`^`(U, 4)), `-`(`*`(`^`(t, 2), `*`(`^`(U, 2)))), `-`(`*`(2, `*`(t, `*`(U)))), `-`(1))) (4.4)
 

> subs(U=0,Q44);
simplify(%);
 

-1 (4.5)
 

-1 (4.5)
 

> Quartic_to_Weierstrass(Q44,[0,I]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(2, `*`(t, `*`(X, `*`(Y, `*`(Z)))))), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(X, `*`(`^`(Z, 2)))))), {X = `+`(`*`(2, `*`(`+`(`-`(`*`(`+`(I), `*`(V))), 1, `*`(t, `*`(U)))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(2, `*`(t, `*`(X, `*`(Y, `*`(Z)))))), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(X, `*`(`^`(Z, 2)))))), {X = `+`(`*`(2, `*`(`+`(`-`(`*`(`+`(I), `*`(V))), 1, `*`(t, `*`(U)))...
(4.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(Z, `*`(`^`(t, 2), `*`(`^`(X, 2))))), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(X, `*`(`^`(Z, 2)))))), {x = X, z = Z, y = `+`(Y, `*`(t, `*`(X)))}, [x, `+`(y, `-`(`*`(t, `*... (4.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(Z, `*`(`^`(t, 2), `*`(`^`(X, 2))))), `-`(`*`(`^`(X, 3))), `-`(`*`(4, `*`(X, `*`(`^`(Z, 2)))))) (4.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (4.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`^`(t, 2), `*`(`^`(x, 2))), `*`(4, `*`(x))) (4.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`^`(t, 2), `*`(`^`(x, 2))), `*`(4, `*`(x))) (4.10)
 

Discriminant = `+`(`*`(256, `*`(`+`(t, `-`(2)), `*`(`+`(t, 2), `*`(`+`(`*`(`^`(t, 2)), 4)))))) (4.10)
 

`+`(jay, `-`(invariant)) = `+`(`/`(`*`(16, `*`(`^`(`+`(`*`(`^`(t, 4)), `-`(12)), 3))), `*`(`+`(t, `-`(2)), `*`(`+`(t, 2), `*`(`+`(`*`(`^`(t, 2)), 4)))))) (4.10)
 

`
` (4.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.44. (4.10)
 

`
` (4.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (4.10)
 

`
` (4.10)
 

The rank of the Mordell-Weil group over C is 1. (4.10)
 

` ` (4.10)
 

>
 

TypeNo.45 

> qc[45]:=(y*z-x^2)^2-y^3*x;
 

`:=`(qc[45], `+`(`*`(`^`(`+`(`*`(y, `*`(z)), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(y, 3), `*`(x))))) (5.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[45]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[45]),x,y);
 

{[[0, 0, 1], 2, 3, 1]} (5.2)
 

> subs(y=t*x+z,qc[45]);
 

`+`(`*`(`^`(`+`(`*`(`+`(`*`(t, `*`(x)), z), `*`(z)), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(`+`(`*`(t, `*`(x)), z), 3), `*`(x)))) (5.3)
 

> Q45:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q45, `+`(`*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(U)), `*`(`+`(`-`(2), `*`(`^`(t, 2)), `-`(`*`(3, `*`(t)))), `*`(`^`(U, 2))), `-`(`*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(`^`(U, 3))))), `-`(`*`(`+`(t, ...
`:=`(Q45, `+`(`*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(U)), `*`(`+`(`-`(2), `*`(`^`(t, 2)), `-`(`*`(3, `*`(t)))), `*`(`^`(U, 2))), `-`(`*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(`^`(U, 3))))), `-`(`*`(`+`(t, ...
(5.4)
 

> subs(U=0,Q45);
simplify(%);
 

1 (5.5)
 

1 (5.5)
 

> Quartic_to_Weierstrass(Q45,[0,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `-`(`*`(2, `*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(Y, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`/`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `-`(`*`(2, `*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(Y, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`/`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `-`(`*`(2, `*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(Y, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`/`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `-`(`*`(2, `*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(Y, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`/`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`*`(2, `*`(t)), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `-`(`*`(2, `*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(Y, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`/`...
(5.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `*`(`^`(t, 4)), `*`(3, `*`(`^`(t, 3))), `*`(8, `*`(t)), 9), `*`(`^`(Z, 3))))), `-`(`*`(4, `*`(`+`(`-`(2), `...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `*`(`^`(t, 4)), `*`(3, `*`(`^`(t, 3))), `*`(8, `*`(t)), 9), `*`(`^`(Z, 3))))), `-`(`*`(4, `*`(`+`(`-`(2), `...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(4, `*`(`^`(t, 2))), `*`(`^`(t, 4)), `*`(3, `*`(`^`(t, 3))), `*`(8, `*`(t)), 9), `*`(`^`(Z, 3))))), `-`(`*`(4, `*`(`+`(`-`(2), `...
(5.7)
 

> mapfactor(subs({X=4*X,Y=8*Y},%[1]/64),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(4, `*`(`^`(t, 2))), `*`(`^`(t, 4)), `*`(3, `*`(`^`(t, 3))), `*`(8, `*`(t)), 9), `*`(`^`(Z, 3)))), `-`(`*`(`+`(`-`(2), `*`(`^`(t, 2)), `...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(4, `*`(`^`(t, 2))), `*`(`^`(t, 4)), `*`(3, `*`(`^`(t, 3))), `*`(8, `*`(t)), 9), `*`(`^`(Z, 3)))), `-`(`*`(`+`(`-`(2), `*`(`^`(t, 2)), `...
(5.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (5.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(2), `*`(`^`(t, 2)), `-`(`*`(3, `*`(t)))), `*`(`^`(x, 2))), `*`(`+`(`-`(4), `*`(2, `*`(t)), `-`(`*`(`^`(t, 2))), `-`(`*`(2, `*`(`^`(t, 3))))), `*`(x)), ... (5.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(2), `*`(`^`(t, 2)), `-`(`*`(3, `*`(t)))), `*`(`^`(x, 2))), `*`(`+`(`-`(4), `*`(2, `*`(t)), `-`(`*`(`^`(t, 2))), `-`(`*`(2, `*`(`^`(t, 3))))), `*`(x)), ... (5.10)
 

Discriminant = `+`(`-`(`*`(2304, `*`(t))), `-`(`*`(2048, `*`(`^`(t, 2)))), `-`(`*`(256, `*`(`^`(t, 4)))), `-`(`*`(64, `*`(`^`(t, 3)))), `-`(4528)) (5.10)
 

`+`(jay, `-`(invariant)) = `+`(`-`(`/`(`*`(256, `*`(`^`(`+`(16, `*`(8, `*`(`^`(t, 2))), `*`(6, `*`(t)), `*`(`^`(t, 4))), 3))), `*`(`+`(`*`(144, `*`(t)), `*`(128, `*`(`^`(t, 2))), `*`(16, `*`(`^`(t, 4)... (5.10)
 

`
` (5.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.45. (5.10)
 

`
` (5.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (5.10)
 

`
` (5.10)
 

The rank of the Mordell-Weil group over C is 1. (5.10)
 

` ` (5.10)
 

>
 

TypeNo.46 

> qc[46]:=(y*z-x^2)^2-y^3*x;
 

`:=`(qc[46], `+`(`*`(`^`(`+`(`*`(y, `*`(z)), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(y, 3), `*`(x))))) (6.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[46]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[46]),x,y);
 

{[[0, 0, 1], 2, 3, 1]} (6.2)
 

> subs(y=t*(x-z),qc[46]);
 

`+`(`*`(`^`(`+`(`*`(t, `*`(`+`(x, `-`(z)), `*`(z))), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(t, 3), `*`(`^`(`+`(x, `-`(z)), 3), `*`(x))))) (6.3)
 

> Q46:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q46, `+`(`*`(`^`(t, 2), `*`(`+`(t, `-`(2)), `*`(U))), `-`(`*`(`+`(t, `-`(1)), `*`(`+`(`*`(`^`(t, 2)), t, 1), `*`(`^`(U, 4))))), `-`(`*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(`+`(t, `-`(1)), `*`(`^`(...
`:=`(Q46, `+`(`*`(`^`(t, 2), `*`(`+`(t, `-`(2)), `*`(U))), `-`(`*`(`+`(t, `-`(1)), `*`(`+`(`*`(`^`(t, 2)), t, 1), `*`(`^`(U, 4))))), `-`(`*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(`+`(t, `-`(1)), `*`(`^`(...
(6.4)
 

> subs(U=1,Q46);
simplify(%);
 

`+`(`*`(`^`(t, 2), `*`(`+`(t, `-`(2)))), `-`(`*`(`+`(t, `-`(1)), `*`(`+`(`*`(`^`(t, 2)), t, 1)))), `-`(`*`(t, `*`(`+`(2, `*`(3, `*`(t))), `*`(`+`(t, `-`(1)))))), `*`(t, `*`(`+`(`-`(2), `*`(3, `*`(`^`(... (6.5)
 

1 (6.5)
 

> Quartic_to_Weierstrass(Q46,[1,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(8, `-`(`*`(2, `*`(`^`(t, 3)))), `-`(`*`(4, `*`(t)))), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`^`(X, 3))), `-`(`*...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(8, `-`(`*`(2, `*`(`^`(t, 3)))), `-`(`*`(4, `*`(t)))), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`^`(X, 3))), `-`(`*...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(8, `-`(`*`(2, `*`(`^`(t, 3)))), `-`(`*`(4, `*`(t)))), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`^`(X, 3))), `-`(`*...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(8, `-`(`*`(2, `*`(`^`(t, 3)))), `-`(`*`(4, `*`(t)))), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`^`(X, 3))), `-`(`*...
(6.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(8, `*`(`^`(t, 6)), `*`(4, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t,...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(8, `*`(`^`(t, 6)), `*`(4, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t,...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(8, `*`(`^`(t, 6)), `*`(4, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t,...
(6.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(8, `*`(`^`(t, 6)), `*`(4, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t,...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(`+`(8, `*`(`^`(t, 6)), `*`(4, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t,...
(6.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (6.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(x, 2))), `*`(`+`(`*`(2, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t, 2))), 12, `-`(`*`(16, `*`(t)))), `*`(x)), 8, `*... (6.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(x, 2))), `*`(`+`(`*`(2, `*`(`^`(t, 4))), `*`(4, `*`(`^`(t, 2))), 12, `-`(`*`(16, `*`(t)))), `*`(x)), 8, `*... (6.10)
 

Discriminant = `+`(`-`(`*`(16, `*`(`^`(t, 9), `*`(`+`(`*`(128, `*`(t)), `-`(256), `*`(23, `*`(`^`(t, 3))), `*`(128, `*`(`^`(t, 2))))))))) (6.10)
 

`+`(jay, `-`(invariant)) = `+`(`/`(`*`(256, `*`(`^`(`+`(`-`(16), `*`(5, `*`(`^`(t, 2))), `*`(8, `*`(t))), 3))), `*`(`^`(t, 3), `*`(`+`(`*`(128, `*`(t)), `-`(256), `*`(23, `*`(`^`(t, 3))), `*`(128, `*`... (6.10)
 

`
` (6.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.46. (6.10)
 

`
` (6.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (6.10)
 

`
` (6.10)
 

The rank of the Mordell-Weil group over C is 1. (6.10)
 

` ` (6.10)
 

>
 

TypeNo.47 

> qc[47]:=(y*z-x^2)^2-y^3*x;
 

`:=`(qc[47], `+`(`*`(`^`(`+`(`*`(y, `*`(z)), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(y, 3), `*`(x))))) (7.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[47]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[47]),x,y);
 

{[[0, 0, 1], 2, 3, 1]} (7.2)
 

> subs(z=t*(x-y),qc[47]);
 

`+`(`*`(`^`(`+`(`*`(y, `*`(t, `*`(`+`(x, `-`(y))))), `-`(`*`(`^`(x, 2)))), 2)), `-`(`*`(`^`(y, 3), `*`(x)))) (7.3)
 

> Q47:=mapfactor(subs({y=1,x=U},%),U);
 

`:=`(Q47, `+`(`-`(`*`(`+`(`*`(2, `*`(`^`(t, 2))), 1), `*`(U))), `-`(`*`(2, `*`(t, `*`(`^`(U, 3))))), `*`(`^`(U, 4)), `*`(t, `*`(`+`(2, t), `*`(`^`(U, 2)))), `*`(`^`(t, 2)))) (7.4)
 

> subs(U=1,Q47);
simplify(%);
 

`+`(`-`(`*`(`^`(t, 2))), `-`(`*`(2, `*`(t))), `*`(t, `*`(`+`(2, t)))) (7.5)
 

0 (7.5)
 

> Quartic_to_Weierstrass(Q47,[1,0]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))...
(7.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))...
(7.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(2, `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(`+`(t, `-`(2)), `*`(X, `*`(`^`(Z, 2))))))), `-`(`*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2), `*`(`^`(Z, 3))... (7.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (7.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(x, 2))), `*`(2, `*`(`+`(t, `-`(2)), `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(x)))), `*`(`^`(`+`(`*`(2, `*`(t))... (7.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`*`(`^`(t, 2)), `-`(`*`(4, `*`(t))), 6), `*`(`^`(x, 2))), `*`(2, `*`(`+`(t, `-`(2)), `*`(`+`(`*`(2, `*`(t)), `-`(3)), `*`(x)))), `*`(`^`(`+`(`*`(2, `*`(t))... (7.10)
 

Discriminant = `+`(`*`(16, `*`(`+`(`*`(4, `*`(`^`(t, 3))), `-`(`*`(20, `*`(`^`(t, 2)))), `-`(`*`(4, `*`(t))), `-`(3)), `*`(`^`(`+`(`*`(2, `*`(t)), `-`(3)), 2))))) (7.10)
 

`+`(jay, `-`(invariant)) = `+`(`/`(`*`(256, `*`(`^`(t, 3), `*`(`^`(`+`(`*`(16, `*`(t)), `-`(6), `*`(`^`(t, 3)), `-`(`*`(8, `*`(`^`(t, 2))))), 3)))), `*`(`+`(`*`(4, `*`(`^`(t, 3))), `-`(`*`(20, `*`(`^`... (7.10)
 

`
` (7.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.47. (7.10)
 

`
` (7.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (7.10)
 

`
` (7.10)
 

The rank of the Mordell-Weil group over C is 1. (7.10)
 

` ` (7.10)
 

>
 

TypeNo.48 

> qc[48]:=x^4+y^4+x^3*y-x*y^2*z;
 

`:=`(qc[48], `+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `*`(`^`(x, 3), `*`(y)), `-`(`*`(x, `*`(`^`(y, 2), `*`(z)))))) (8.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[48]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[48]),x,y);
 

{[[0, 0, 1], 3, 3, 2]} (8.2)
 

> subs(y=t*x-z,qc[48]);
 

`+`(`*`(`^`(x, 4)), `*`(`^`(`+`(`*`(t, `*`(x)), `-`(z)), 4)), `*`(`^`(x, 3), `*`(`+`(`*`(t, `*`(x)), `-`(z)))), `-`(`*`(x, `*`(`^`(`+`(`*`(t, `*`(x)), `-`(z)), 2), `*`(z))))) (8.3)
 

> Q48:=mapfactor(subs({z=1,x=U},%),U);
 

`:=`(Q48, `+`(`-`(`*`(`+`(`*`(4, `*`(t)), 1), `*`(U))), `*`(2, `*`(t, `*`(`+`(`*`(3, `*`(t)), 1), `*`(`^`(U, 2))))), `*`(`+`(`*`(`^`(t, 4)), 1, t), `*`(`^`(U, 4))), `-`(`*`(`+`(`*`(4, `*`(`^`(t, 3))),... (8.4)
 

> subs(U=0,Q48);
simplify(%);
 

1 (8.5)
 

1 (8.5)
 

> Quartic_to_Weierstrass(Q48,[0,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(4, `*`(t))), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 2)))), `-`(`*`(8, `*`(`^`(t, 3)))), `-`(2)), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(4, `*`(t))), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 2)))), `-`(`*`(8, `*`(`^`(t, 3)))), `-`(2)), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(4, `*`(t))), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 2)))), `-`(`*`(8, `*`(`^`(t, 3)))), `-`(2)), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(4, `*`(t))), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 2)))), `-`(`*`(8, `*`(`^`(t, 3)))), `-`(2)), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `*`(`+`(`-`(`*`(4, `*`(t))), `-`(1)), `*`(X, `*`(Y, `*`(Z)))), `*`(`+`(`-`(`*`(2, `*`(`^`(t, 2)))), `-`(`*`(8, `*`(`^`(t, 3)))), `-`(2)), `*`(Y, `*`(`^`(Z, 2)))), `-`(`*`(`...
(8.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(2, `*`(t)), 1), `*`(`+`(`*`(2, `*`(`^`(t, 2))), t, 2), `*`(`+`(`*`(2, `*`(`^`(t, 3))), `-`(`*`(2, `*`(t))), 1), `*`(`^`(Z, 3)))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(2, `*`(t)), 1), `*`(`+`(`*`(2, `*`(`^`(t, 2))), t, 2), `*`(`+`(`*`(2, `*`(`^`(t, 3))), `-`(`*`(2, `*`(t))), 1), `*`(`^`(Z, 3)))...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(64, `*`(`+`(`*`(2, `*`(t)), 1), `*`(`+`(`*`(2, `*`(`^`(t, 2))), t, 2), `*`(`+`(`*`(2, `*`(`^`(t, 3))), `-`(`*`(2, `*`(t))), 1), `*`(`^`(Z, 3)))...
(8.7)
 

> mapfactor(subs({X=4*X,Y=8*Y},%[1]/64),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(2, `*`(t)), 1), `*`(`+`(`*`(2, `*`(`^`(t, 2))), t, 2), `*`(`+`(`*`(2, `*`(`^`(t, 3))), `-`(`*`(2, `*`(t))), 1), `*`(`^`(Z, 3)))))), `-`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(2, `*`(t)), 1), `*`(`+`(`*`(2, `*`(`^`(t, 2))), t, 2), `*`(`+`(`*`(2, `*`(`^`(t, 3))), `-`(`*`(2, `*`(t))), 1), `*`(`^`(Z, 3)))))), `-`...
(8.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (8.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(2, `*`(t, `*`(`+`(`*`(3, `*`(t)), 1), `*`(`^`(x, 2))))), `*`(`+`(`*`(`^`(t, 2)), `-`(3), `*`(12, `*`(`^`(t, 4))), `*`(8, `*`(`^`(t, 3)))), `*`(x)), `*`(`+`(`*`...
`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(2, `*`(t, `*`(`+`(`*`(3, `*`(t)), 1), `*`(`^`(x, 2))))), `*`(`+`(`*`(`^`(t, 2)), `-`(3), `*`(12, `*`(`^`(t, 4))), `*`(8, `*`(`^`(t, 3)))), `*`(x)), `*`(`+`(`*`...
(8.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(2, `*`(t, `*`(`+`(`*`(3, `*`(t)), 1), `*`(`^`(x, 2))))), `*`(`+`(`*`(`^`(t, 2)), `-`(3), `*`(12, `*`(`^`(t, 4))), `*`(8, `*`(`^`(t, 3)))), `*`(x)), `*`(`+`(`*`...
`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(2, `*`(t, `*`(`+`(`*`(3, `*`(t)), 1), `*`(`^`(x, 2))))), `*`(`+`(`*`(`^`(t, 2)), `-`(3), `*`(12, `*`(`^`(t, 4))), `*`(8, `*`(`^`(t, 3)))), `*`(x)), `*`(`+`(`*`...
(8.10)
 

Discriminant = `+`(`*`(16, `*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(`+`(9, `*`(4, `*`(t))), 2)))))) (8.10)
 

`+`(jay, `-`(invariant)) = `+`(`/`(`*`(256, `*`(`^`(`+`(`*`(`^`(t, 2)), 9), 3))), `*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(`+`(9, `*`(4, `*`(t))), 2)))))) (8.10)
 

`
` (8.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.44. (8.10)
 

`
` (8.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (8.10)
 

`
` (8.10)
 

The rank of the Mordell-Weil group over C is 1. (8.10)
 

` ` (8.10)
 

>
 

TypeNo.49 

> qc[49]:=x^4+y^4-x*y^2*z;
 

`:=`(qc[49], `+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(x, `*`(`^`(y, 2), `*`(z)))))) (9.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[50]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[49]),x,y);
 

{[[0, 0, 1], 3, 3, 2]} (9.2)
 

> subs(z=t*y+2*x,qc[49]);
 

`+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(x, `*`(`^`(y, 2), `*`(`+`(`*`(t, `*`(y)), `*`(2, `*`(x)))))))) (9.3)
 

> Q49:=mapfactor(subs({x=1,y=U},%),U);
 

`:=`(Q49, `+`(1, `*`(`^`(U, 4)), `-`(`*`(t, `*`(`^`(U, 3)))), `-`(`*`(2, `*`(`^`(U, 2)))))) (9.4)
 

> subs(U=0,Q49);
simplify(%);
 

1 (9.5)
 

1 (9.5)
 

> Quartic_to_Weierstrass(Q49,[0,1]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(2, `*`(t, `*`(Y, `*`(`^`(Z, 2)))))), `-`(`*`(`^`(X, 3))), `*`(2, `*`(`^`(X, 2), `*`(Z))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `-`(`*`(8, `*`(`^`(Z, 3))))), {X = `+`(`*`...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(2, `*`(t, `*`(Y, `*`(`^`(Z, 2)))))), `-`(`*`(`^`(X, 3))), `*`(2, `*`(`^`(X, 2), `*`(Z))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `-`(`*`(8, `*`(`^`(Z, 3))))), {X = `+`(`*`...
(9.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), 8), `*`(`^`(Z, 3)))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `*`(2, `*`(`^`(X, 2), `*`(Z)))), {x = X, z = Z, y = `+`(Y, `*`(t, `*`... (9.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`*`(`^`(t, 2)), 8), `*`(`^`(Z, 3)))), `*`(4, `*`(X, `*`(`^`(Z, 2)))), `*`(2, `*`(`^`(X, 2), `*`(Z)))) (9.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (9.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `-`(`*`(2, `*`(`^`(x, 2)))), `-`(`*`(4, `*`(x))), `*`(`^`(t, 2)), 8) (9.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `-`(`*`(2, `*`(`^`(x, 2)))), `-`(`*`(4, `*`(x))), `*`(`^`(t, 2)), 8) (9.10)
 

Discriminant = `+`(`-`(`*`(16, `*`(`^`(t, 2), `*`(`+`(256, `*`(27, `*`(`^`(t, 2))))))))) (9.10)
 

`+`(jay, `-`(invariant)) = `+`(`-`(`/`(`*`(1048576), `*`(`^`(t, 2), `*`(`+`(256, `*`(27, `*`(`^`(t, 2))))))))) (9.10)
 

`
` (9.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.49. (9.10)
 

`
` (9.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (9.10)
 

`
` (9.10)
 

The rank of the Mordell-Weil group over C is 1. (9.10)
 

` ` (9.10)
 

TypeNo.50 

> qc[50]:=x^4+y^4-x*y^2*z;
 

`:=`(qc[50], `+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(x, `*`(`^`(y, 2), `*`(z)))))) (10.1)
 

> with(plots):

with(algcurves):
plot_real_curve(subs(z=1,qc[50]),x,y);
 

Plot_2d
 

> singularities(subs(z=1,qc[50]),x,y);
 

{[[0, 0, 1], 3, 3, 2]} (10.2)
 

> subs(z=t*(y-x)+2*x,qc[50]);
 

`+`(`*`(`^`(x, 4)), `*`(`^`(y, 4)), `-`(`*`(x, `*`(`^`(y, 2), `*`(`+`(`*`(t, `*`(`+`(y, `-`(x)))), `*`(2, `*`(x)))))))) (10.3)
 

> Q50:=mapfactor(subs({x=1,y=U},%),U);
 

`:=`(Q50, `+`(`*`(`^`(U, 4)), `*`(`+`(t, `-`(2)), `*`(`^`(U, 2))), `-`(`*`(t, `*`(`^`(U, 3)))), 1)) (10.4)
 

> subs(U=1,Q50);
simplify(%);
 

0 (10.5)
 

0 (10.5)
 

> Quartic_to_Weierstrass(Q46,[1,0]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(Z, 2), `*`(X))))), `-`(`*`(`^`(t, 2), `*`(`^`(Z, ...
`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `-`(`*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(Z, 2), `*`(X))))), `-`(`*`(`^`(t, 2), `*`(`^`(Z, ...
(10.6)
 

> step5(%[1],{x=X,z=Z,y=Y},{x,y,z});
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(2, `*`(`+`(t, `-`(2)), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(Z, 2), `*`(X))))), `-`(`*`(`^`(t, 2), `*`(`^`(Z, 3))))), {x... (10.7)
 

> mapfactor(subs({X=X,Y=Y},%[1]),[X,Y]);
 

`+`(`*`(`^`(Y, 2), `*`(Z)), `-`(`*`(`^`(X, 3))), `*`(2, `*`(`+`(t, `-`(2)), `*`(`^`(X, 2), `*`(Z)))), `-`(`*`(t, `*`(`+`(t, `-`(4)), `*`(`^`(Z, 2), `*`(X))))), `-`(`*`(`^`(t, 2), `*`(`^`(Z, 3))))) (10.8)
 

> Elliptic_surface(%);
 

`
     The curve you have entered is:` (10.9)
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(`^`(x, 2))), `*`(t, `*`(`+`(t, `-`(4)), `*`(x))), `*`(`^`(t, 2))) (10.9)
 

> Show_data();
 

`*`(`^`(y, 2)) = `+`(`*`(`^`(x, 3)), `*`(`+`(`-`(`*`(2, `*`(t))), 4), `*`(`^`(x, 2))), `*`(t, `*`(`+`(t, `-`(4)), `*`(x))), `*`(`^`(t, 2))) (10.10)
 

Discriminant = `+`(`-`(`*`(16, `*`(`^`(t, 3), `*`(`+`(32, `-`(`*`(13, `*`(t))), `*`(4, `*`(`^`(t, 2))))))))) (10.10)
 

`+`(jay, `-`(invariant)) = `+`(`-`(`/`(`*`(256, `*`(`^`(`+`(16, `-`(`*`(4, `*`(t))), `*`(`^`(t, 2))), 3))), `*`(`^`(t, 3), `*`(`+`(32, `-`(`*`(13, `*`(t))), `*`(4, `*`(`^`(t, 2))))))))) (10.10)
 

`
` (10.10)
 

This is a rational elliptic surface; Oguiso-Shioda type No.50. (10.10)
 

`
` (10.10)
 

Typesetting:-mrow(Typesetting:-mrow(Typesetting:-mi( (10.10)
 

`
` (10.10)
 

The rank of the Mordell-Weil group over C is 1. (10.10)
 

` ` (10.10)
 

>