isLinearComplex F
We say that a (nonzero) $\ZZ^r$graded complex F is linear if its first nonzero module is generated in a single multidegree and all of its maps (including the zero maps) have degree at most 1. For instance, if F_i is zero for $i<0$ and F_0 is generated in degree $0\in\ZZ^r$, then F_i should be generated in multidegrees with sum at most $i$ for $i>0$. If F is zero then the function returns true.









It is possible for a complex to have differential matrices containing only linear entries yet be nonlinear by the definition above.
The object isLinearComplex is a method function.