SymmetricReduction

SymmetricReduction[f,{x1,…,xn}] gives a pair of polynomials {p,q} in x1,…,xn such that f==p+q, where p is the symmetric part and q is the remainder.

SymmetricReduction[f,{x1,…,xn},{s1,…,sn}] gives the pair {p,q} with the elementary symmetric polynomials in p replaced by s1,…,sn.

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