6.27.2 Polynomials of several variables: %%%{ %%%}
A polynomial of several variables can be represented in different ways:
-
by a symbolic expression.
- by a dense recursive 1-d representation like above.
- by a sum of monomials with non-zero coefficients (distributed sparse
representation).
A monomial with several variables is represented by a coefficient and a
list of integers (interpreted as powers of a variable list). The
delimiters for monomials are %%%{ and
%%%}.
For example 3x2y is represented by
%%%{3,[2,1]%%%} with respect to the variable list
[x,y]), and 2x3y2z − 5 xz is represented by
%%%{2,[3,2,1]%%%} - %%%{5,[1,0,1]%%%}
with respect to the variable list [x,y,z].
For a sparse representation, a single variable polynomial can be
regarded as a multivariate polynomial with one variable.