“…When F is not σ α,0 -semistable, the argument is slightly more complicated. Our main tools are inequalities in [PR20], [PY20, Proposition 4.1], and [Li16, Proposition 3.2], which allow us to bound the rank and first two Chern characters ch 1 , ch 2 of the destabilizing objects and their cohomology objects. Since F ∈ A X , by using the Euler characteristics χ(O X [1], −) and χ(−, O X (−1)[2]) we can obtain a bound on ch 3 .…”