Ali, many thanks for your comments which are very instructive. Actually I am trying to understand anything in the Floris van Doorn's thesis, particularly the formalization in HoTT for the *Atiyah*-*Hirzebruch spectral* sequence and the *Leray*-*Serre spectral* sequence. > -- You received this message because you are subscribed to the Google Groups "Homotopy Type Theory" group. To unsubscribe from this group and stop receiving emails from it, send an email to HomotopyTypeTheory+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.