Clarify scope of coefficient positivity in log assessment

experiments/LOG_DENSITY_ASSESSMENT_2026-09-19.md

@@ -56,8 +56,8 @@ This retains the original roots whose coefficient vectors are positive. The
 Gauss-Legendre nodal basis has sign-changing basis functions, so positive `r_j`
 does not imply nonnegative `rho_h`. In particular, taking logarithms of the
 already-positive coefficients at the measured n=1.5 root and applying this
-coordinate change would reproduce its negative polynomial exactly. No additional
-constraint on positive coefficients removes that root.
+coordinate change would reproduce its negative polynomial exactly. Requiring
+positive coefficients alone does not remove that root.
 
 ### A pointwise exponential of an independent FE field