1. Local structures
This chapter serves for the first half of the commutative algebra preparation of
the remaining part of the paper. The key result is
Theorem 1.8.5, expressing that for any
ring A, there exists an ind-étale faithfully flat A-algebra D with D
w-contractible. That is to say, every affine scheme has a w-contractible cover
in the "pro-(étale site)".