I am currently reading Künneth spectral sequence, which is given below.
Let $R$ be a ring and A$=\big\{A_n,d_n:A_n\longrightarrow A_{n-1}\big|d_{n-1}\circ d_n=0\big\}_{n\in \Bbb Z}$ be a chain complex of right $R$-modules with each $A_n$ is flat and $A_n=0$ when $n<0$. Let C$=\big\{C_n,\partial_n:C_n\longrightarrow C_{n-1}\big|\partial_{n-1}\circ \partial_n=0\big\}_{n\in \Bbb Z}$ be a chain complex of left $R$-modules with $C_n=0$ if $n<0$. Then, We have two spectral sequences $^\text{I}E,\ ^\text{II}E$ both converging to $H_n(\textbf{A}\otimes_R\textbf{C})$ such that $$^\text{II}E^2_{p,q}\simeq\bigoplus_{l+k=q}\text{Tor}^R_p\bigg(H_k(\textbf{A}), H_l(\textbf{C})\bigg)\text{ and }^\text{I}E^2_{p,q}=\begin{cases} H_p(\textbf{ A}\otimes_R\textbf{ C}) & \text{ if }q=0,\\0 & \text{ if }q\not=0.\end{cases}$$
Now, the proof based on Künneth formula for homology. Also, these spectral sequences can give an alternative proof of Künneth formula for homology, when chain complexes are positive. So, the argument is somewhat cyclic. I am looking for an alternative proof of Künneth spectral sequence. Is it possible? Any help will be appreciated. Thanks in advance.