We construct a sequence of computable real metrics pairwise incomparable under weak reducibility < ch and located above the standard real metric w. r. t. computable reducibility <c. Iterating the construction, we obtain that the ordering (P(ω), ⸦) of subsets of ω is embeddable into the ordering of ch-degrees of real metrics above the standard metric. It is also proved that the countable atomless Boolean algebra is embeddable with preservation of joins and meets into the ordering of c-degrees of computable real metrics.
Предметные области OECD FOS+WOS
- 1.01 МАТЕМАТИКА