Assertion: sequence's number | /r/HasProperty | natural
Facets:
Source sentences:
text: If we take a series of short exact sequences linked by chain complexes (that is, a short exact sequence of chain complexes, or from another point of view, a chain complex of short exact sequences), then we can derive from this a long exact sequence (i.e. an exact sequence indexed by the natural numbers) on homology by application of the zig-zag lemma.
text: The prime numbers are the natural numbers bigger than 1 that have no divisors but 1 and themselves.