Magma Coercion Syntax - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-24T05:31:46Z http://mathoverflow.net/feeds/question/87234 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/87234/magma-coercion-syntax Magma Coercion Syntax bobuhito 2012-02-01T14:53:32Z 2012-03-27T18:42:04Z <p>Any Magma experts who know what I should write below in place of "Roots(ysoln)"? I basically want the roots of a FldFunRatMElt (variable here happens to show as "\$.2"). I would guess there's some simple coercion needed, but I've had no luck finding examples for this on the internet. I really just need to know the rational roots. Thanks!</p> <pre><code>PP&lt;x,y,z&gt;:=ProjectiveSpace(Rationals(),2); CU:=Curve(PP, (z + x - y)*(z - x + y)*(-z + x + y)*(z + x + y)); curve:=DefiningPolynomials(CU)[1]; ysoln:=Evaluate(curve,[1,y,1]); ysoln; Type(ysoln); ysoln:=Evaluate(ysoln,[1,y,1])/y; ysoln:=Evaluate(ysoln,[1,y,1])*y; // Other things really happen above, but denominator becomes 1 ysoln; Type(ysoln); // I would like to just do this Roots(ysoln); // but Magma refuses... // I know the Roots function works if set-up properly: R&lt;y&gt;:=PolynomialRing(Rationals()); fy:=y^3-8; Roots(fy); </code></pre>