The construction of the Serre spectral sequence is done up to 11 sorry's, all which are marked with 'TODO FOR SSS'. 8 of them are equivalences related to cohomology (6 of which are corollaries of the other 2), 2 of them are calculations on int, and the last is in the definition of a spectrum map.
Note: the Serre spectral sequence only works for unreduced cohomology, so we need some results for that
For reduced homology we might get a similar result if we replace the sigma in the RHS by a dependent version of the smash product
