Thursday, 26 October 2000 Day 14: Math 697R Applicable Algebraic Geometry ___________________________________________________________ Make up Day: Nov 7 (Tu), 8 (Wed) 14 16(Th) 20(Mon) There will be a makeup day in December __________________________________________________________ - Definition: Standard Monomial - Images of Standard Monomials for monomial ideals - Macaulay's Theorem for k[T]/I - Algorithm for computing in quotient rings - Definition: S-polynomials - Buchberger's Criterion - The Buchberger Algorithm - Corollary: GB computed without changing the field - Example: S_3 invariants; Linear polynomials SYMBOLIC SOLUTION OF POLYNOMIAL EQUATIONS 5 questions about a system of equations Solutions are V(I). Theorem. V(I) finite iff only finitely many Standard monomials Corollary. # V(I) <= # Standard Monomials Definition: degree I B\'ezout's Theorem. Definition. Eliminant: monic generator of I\cap K[t_i] Theorem. Roots of an eliminants are the set of i-coords of roots of I Shape Lemma.