@@ -1,146 +1,146 @@ -REDUCE 3.6, 15-Jul-95, patched to 6 Mar 96 ... - - -I_setting(x,y,z); - - - -torder revgradlex; - - -{{},lex} - - -u := I(x*z-y**2, x**3-y*z); - - - 2 3 -u := i(x*z - y ,x - y*z) - -y member I(x,y^2); - - -0 - -x member I(x,y^2); - - -1 - -I(x,y^2) subset I(x,y); - - -1 - % yes -I(x,y) subset I(x,y^2); - - -0 - % no - -% examples taken from Cox, Little, O'Shea: "Ideals, Varieties and Algorithms" - - - - -q1 := u .: I(x); - - - 3 2 2 2 -q1 := i(x - y*z,x *y - z , - x*z + y ) - % quotient ideal - -q2 := u .+ I(x^2 * y - z^2); - - - 3 2 2 2 -q2 := i(x - y*z,x *y - z , - x*z + y ) - % sum ideal - -if q1 .= q2 then write "same ideal"; - - -same ideal - % test equality - -intersection(u,I(y)); - - - 3 2 2 2 2 3 -i(x *y - y *z,x *y - y*z , - x*y*z + y ) - % ideal intersection - -u .: I(y); - - - 3 2 2 2 -i(x - y*z,x *y - z , - x*z + y ) - - -u .: I(x,y); - - - 3 2 2 2 -i(x - y*z,x *y - z , - x*z + y ) - - -%----------------------------------------------------- - -u1 := I(x,y^2); - - - 2 -u1 := i(x,y ) - -u1u1:= u1 .* u1; - - - 4 2 2 -u1u1 := i(y ,x*y ,x ) - % square ideal -u0 :=I(x,y); - - -u0 := i(x,y) - - -% test equality/inclusion for u1,u1u1,u0 - -u1 .= u1u1; - - -0 - % no - -u1 subset u1u1; - - -0 - % no - -u1u1 subset u1; - - -1 - % yes - -u1 .= u0; - - -0 - % no - -u1 subset u0; - - -1 - % yes - -intersection (I(x) , I(x^2,x*y,y^2)) .= intersection(I(x) , I(x^2,y)); - - -1 - - -end; -(TIME: ideals 330 330) +REDUCE 3.6, 15-Jul-95, patched to 6 Mar 96 ... + + +I_setting(x,y,z); + + + +torder revgradlex; + + +{{},lex} + + +u := I(x*z-y**2, x**3-y*z); + + + 2 3 +u := i(x*z - y ,x - y*z) + +y member I(x,y^2); + + +0 + +x member I(x,y^2); + + +1 + +I(x,y^2) subset I(x,y); + + +1 + % yes +I(x,y) subset I(x,y^2); + + +0 + % no + +% examples taken from Cox, Little, O'Shea: "Ideals, Varieties and Algorithms" + + + + +q1 := u .: I(x); + + + 3 2 2 2 +q1 := i(x - y*z,x *y - z , - x*z + y ) + % quotient ideal + +q2 := u .+ I(x^2 * y - z^2); + + + 3 2 2 2 +q2 := i(x - y*z,x *y - z , - x*z + y ) + % sum ideal + +if q1 .= q2 then write "same ideal"; + + +same ideal + % test equality + +intersection(u,I(y)); + + + 3 2 2 2 2 3 +i(x *y - y *z,x *y - y*z , - x*y*z + y ) + % ideal intersection + +u .: I(y); + + + 3 2 2 2 +i(x - y*z,x *y - z , - x*z + y ) + + +u .: I(x,y); + + + 3 2 2 2 +i(x - y*z,x *y - z , - x*z + y ) + + +%----------------------------------------------------- + +u1 := I(x,y^2); + + + 2 +u1 := i(x,y ) + +u1u1:= u1 .* u1; + + + 4 2 2 +u1u1 := i(y ,x*y ,x ) + % square ideal +u0 :=I(x,y); + + +u0 := i(x,y) + + +% test equality/inclusion for u1,u1u1,u0 + +u1 .= u1u1; + + +0 + % no + +u1 subset u1u1; + + +0 + % no + +u1u1 subset u1; + + +1 + % yes + +u1 .= u0; + + +0 + % no + +u1 subset u0; + + +1 + % yes + +intersection (I(x) , I(x^2,x*y,y^2)) .= intersection(I(x) , I(x^2,y)); + + +1 + + +end; +(TIME: ideals 330 330)