# Definition talk:Null Sequence (Homological Algebra)

I'm not sure. "Differential Complex Corresponds with a Null Sequence" to me means that given a differential complex, one can associate a null sequence. The result I had in mind was the stronger statement that given a differential complex $M$ we can associate a null sequence $\hat M$, and given a null sequence $T$ we can associate a differential complex $T^\star$. Moreover we have $(\hat M)^\star = M$.

Thus we have a bijection between null sequences and differential complexes; but since the categories aren't small, the statement has to be "Categories of Differential Complexes and Null Sequences are Isomorphic". I wanted to avoid this statement, since this involves defining both these categories and proving that they're categories first, and since I only know the "let's ignore set-theoretic problems" kind of category theory, I thought it best to leave that area alone. --Linus44 (talk) 22:12, 27 May 2013 (UTC)

- fair enough --prime mover (talk) 22:14, 27 May 2013 (UTC)