exact centered-average operator identity checked through D^12
A_Delta = product_a sinh(Delta_a D/2)/(Delta_a D/2)
coefficients:
  D^0: 1
  D^2: -e2/12
  D^4: e2^2/360
  D^6: -e2^3/20160 + delta^2/60480
  D^8: (e2^4 - e2*delta^2)/1814400
Cayley-block logarithmic derivative reduction checked exactly
disc(x^mu-t) trace formula checked for 2 <= mu <= 9 and t in {2,3}
persistent-fat-point and mixed-support discriminants vanish as claimed
all exact checks passed