#### UserFunction Sum

Sum(u,v:DPOLID(C,v,O))

The arguments $u$ and $v$ have the type $DPOLID$ which abbreviates Distributive Polynomial Ideal.
The meaning of its parameters is as follows.

$C$: Type of coefficients.

$v=\{v_1,v_2,\ldots \}$: Distributive variables in decreasing order.

$O=LEX|GRLEX|GREVLEX$: Term order.

Specification. Generators for the sum ideal of $u$ and $v$ are returned. In general they are not a Groebner basis.

Examples. The input for the examples is given in Reduce algebraic mode syntax. The output for each minisession
is returned in a separate window.

I:= {x*y+2*x-3,x**2+3*x+y};

J:={3*x*y-x+y**2-1,x+3*y-1};

Sum(I,J|DPOLID(RATF Q,{x,y},GRLEX)|);

The given ideals:
$<xy+2x-3,x^{2}+3x+y>,$
$<3xy+y^{2}-x-1,x+3y-1>$
The sum ideal:
$<xy+2x-3,x^{2}+3x+y>,3xy+y^{2}-x-1,x+3y-1>$

Related Functions. Product, Lcm.

References.

W.W. Adams, P. Loustaunau, An Introduction to Groebner Bases, American Mathematical Society, 1994.

D. Cox, J. Little, D. O'Shea, Ideals, Varieties and Algorithms Using Algebraic Geometry,
Undergraduate Texts in Mathematics, Springer, 1992 and 1998.

G.M. Greuel, G. Pfister, A Singular Introduction to Commutative Algebra, Springer, 2002.

M. Kreuzer, L. Robbiano, Using Computational Commutative Algebra I and II, Springer, 2000.