CoDepth -- Option for syzygyModule(-k,M,CoDepth => m)

Allows the user to specify a number m (which must be at least CoDepth M), for more efficient computation.

Does not check that the CoDepth value is correct.

Functions with optional argument named CoDepth:

• approximation(...,CoDepth=>...) -- see approximation -- returns pair of components of the map from the MCM approximation
• auslanderInvariant(...,CoDepth=>...) -- see auslanderInvariant -- measures failure of surjectivity of the essential MCM approximation
• coApproximation(...,CoDepth=>...) -- see coApproximation -- Maximal Cohen-Macaulay co-approximation of M
• syzygyModule(...,CoDepth=>...) -- see syzygyModule -- Produces the k-th syzygy module (k \in ZZ)