Unstable
Alternating polynomials are an unstable phenomenon (in the language of stable homotopy theory): the ring of symmetric polynomials in n variables can be obtained from the ring of symmetric polynomials in arbitrarily many variables by evaluating all variables above to zero: symmetric polynomials are thus stable or compatibly defined. However, this is not the case for alternating polynomials, in particular the Vandermonde polynomial.
Read more about this topic: Alternating Polynomial