Proposition 4.32 (Stability of real stable). Assuming that:

  • p(z1,…,zn) is real stable

Then the following are also:
  • p(zσ(1),…,zσ(n)), σ∈Sn.

  • p(az1,z2,…,zn), a∈ℝ≥0.

  • p(z2,z2,z3,…,zn).

  • p(c,z2,…,zn), c∈H∪ℝ.

  • z1d1p(−1z1,z2,…,zn).

  • ∂z1p(z1,…,zn).

  • MAP⁡(p(z1,…⁡,zn)). MAP⁡(z1z2+z2z32+2z1z4+z2z32)=z1z2+2z1z4.

  • If p,q are real stable, then so is pq.