Short documentation for the Drell-Yan rapidity code written by Frank Petriello.
For more details please contact Frank.

(1) The main program is a loop that calculates D (NLO) and E (NNLO) 
coefficients, given values of the total CM energy and the lepton invariant mass.
It should be straightforward to modify this format as needed.

(2) Currently, Vegas from the CUBA library (http://www.feynarts.de/cuba/)
is used.

(3) Everything the user may need to modify (invariant mass, energy, NF, scale,
Vegas paramters, etc.)  should be below the line "MODIFY BELOW HERE" in
the main program; comments are given.

(4) The routine "fillpdf" is where the pdf call is performed; it is
currently set up for the MRST set previously sent by James Stirling, with
the bottom pdf set to zero.  This is where the user should rotate the pdfs to
do pn, ppbar scattering (the code assumes pp), change the set, etc.

(5) The NLO and NNLO coefficient function are normalized to the LO result. 
One eccentricity of the code is that it requires the input rapidity value
to be negative (commented on in the code).  Looking at both pn and np
scattering for negative rapidity allows the user to cover the whole range.