2019-05-22 15:33:35 +0200 commented answer What does cohomology_generators actually do? Wow. Reading this bug report convinced me I shouldn't use sage. If even the developers think it's okay to have wrong functions with undocumented bugs... Thank god I didn't include the results in an article before knowing this. 2019-05-22 09:32:05 +0200 commented question What does cohomology_generators actually do? The documentation is misleading then. It says explicitly (not "suggest") that the function it is finding a complement of the set of elements generated by lower-degree generators, as well as coboundaries. 2019-05-21 18:38:46 +0200 received badge ● Student (source) 2019-05-21 17:48:21 +0200 asked a question What does cohomology_generators actually do? I don't understand the output of the function "cohomology_generators" of commutative differential graded algebras. Look at this simple exmaple: A. = GradedCommutativeAlgebra(QQ, degrees = (2,2,1,2)) B = A.cdg_algebra({z:x-y}) B.cohomology_generators(5) {2: [t, y, x]}  It's apparently telling me that t, x and y are all generators of the cohomology algebra in degree 2. But in cohomology, x = y, since dz = x - y!