Let us try to start with a minimum working examle. Start with a graded commutative polynomial algebra, say $A<wa1,wb1,wb2,wc1,wc2,ya,yb, degrees = ((1,0),(1,0),(2,0),(1,0),(2,0),(0,1),(0,1))
with differential
d=A.(wa1:a^2, wb1:0, wb2:wb1*yb^2, wc1:0, wc2: wc1*(ya^2 +yb^2)
.
The differential is of total degree 1, as required, and cohomology computations work fine. The bi-degree of the differential is actually (-1,2), so total degree 1. Furthermore the differential just multiplies by even powers of ya
and yb
Thus the algebra A
, and its cohomology separates into two submodules, Aeven
where the exponents of both ya
and yb
are even, and Aodd
, where at least one of the exponents is odd.
How can I get Sage to create two subcomplexes, and be able to compute their cohomology. As a start, maybe just Aeven
, which is a sub-algebra.
I am pretty new to Sage, and Python, so any help would be appreciated.