C                             April 10, 2002, v6.01
C                             February 23, 2003, v6.1
C
C   Ref[1]: "New Generation of Parton Distributions with Uncertainties from Global QCD Analysis"
C       By: J. Pumplin, D.R. Stump, J.Huston, H.L. Lai, P. Nadolsky, W.K. Tung
C       JHEP 0207:012(2002), hep-ph/0201195
C
C   Ref[2]: "Inclusive Jet Production, Parton Distributions, and the Search for New Physics"
C       By : D. Stump, J. Huston, J. Pumplin, W.K. Tung, H.L. Lai, S. Kuhlmann, J. Owens
C       hep-ph/0303013
C
C   This package contains
C   (1) 4 standard sets of CTEQ6 PDF's (CTEQ6M, CTEQ6D, CTEQ6L, CTEQ6L1) ;
C   (2) 40 up/down sets (with respect to CTEQ6M) for uncertainty studies from Ref[1];
C   (3) updated version of the above: CTEQ6.1M and its 40 up/down eigenvector sets from Ref[2].
C
C  The CTEQ6.1M set provides a global fit that is almost equivalent in every respect
C  to the published CTEQ6M, Ref[1], although some parton distributions (e.g., the gluon)
C  may deviate from CTEQ6M in some kinematic ranges by amounts that are well within the
C  specified uncertainties.
C  The more significant improvements of the new version are associated with some of the
C  40 eigenvector sets, which are made more symmetrical and reliable in (3), compared to (2).

C  Details about calling convention are:
C ---------------------------------------------------------------------------
C  Iset   PDF-set     Description       Alpha_s(Mz)**Lam4  Lam5   Table_File
C ===========================================================================
C Standard, "best-fit", sets:
C --------------------------
C   1    CTEQ6M   Standard MSbar scheme   0.118     326   226    cteq6m.tbl
C   2    CTEQ6D   Standard DIS scheme     0.118     326   226    cteq6d.tbl
C   3    CTEQ6L   Leading Order           0.118**   326** 226    cteq6l.tbl
C   4    CTEQ6L1  Leading Order           0.130**   215** 165    cteq6l1.tbl
C ============================================================================
C For uncertainty calculations using eigenvectors of the Hessian:
C ---------------------------------------------------------------
C     central + 40 up/down sets along 20 eigenvector directions
C                             -----------------------------
C                Original version, Ref[1]:  central fit: CTEQ6M (=CTEQ6M.00)
C                             -----------------------
C  1xx  CTEQ6M.xx  +/- sets               0.118     326   226    cteq6m1xx.tbl
C        where xx = 01-40: 01/02 corresponds to +/- for the 1st eigenvector, ... etc.
C        e.g. 100      is CTEQ6M.00 (=CTEQ6M),
C             101/102 are CTEQ6M.01/02, +/- sets of 1st eigenvector, ... etc.
C                              -----------------------
C                Updated version, Ref[2]:  central fit: CTEQ6.1M (=CTEQ61.00)
C                              -----------------------
C  2xx  CTEQ61.xx  +/- sets               0.118     326   226    ctq61.xx.tbl
C        where xx = 01-40: 01/02 corresponds to +/- for the 1st eigenvector, ... etc.
C        e.g. 200      is CTEQ61.00 (=CTEQ6.1M),
C             201/202 are CTEQ61.01/02, +/- sets of 1st eigenvector, ... etc.
C ===========================================================================
C   ** ALL fits are obtained by using the same coupling strength
C   \alpha_s(Mz)=0.118 and the NLO running \alpha_s formula, except CTEQ6L1
C   which uses the LO running \alpha_s and its value determined from the fit.
C   For the LO fits, the evolution of the PDF and the hard cross sections are
C   calculated at LO.  More detailed discussions are given in the references.
C
C   The table grids are generated for 10^-6 < x < 1 and 1.3 < Q < 10,000 (GeV).
C   PDF values outside of the above range are returned using extrapolation.
C   Lam5 (Lam4) represents Lambda value (in MeV) for 5 (4) flavors.
C   The matching alpha_s between 4 and 5 flavors takes place at Q=4.5 GeV,
C   which is defined as the bottom quark mass, whenever it can be applied.
C
C   The Table_Files are assumed to be in the working directory.
C
C   Before using the PDF, it is necessary to do the initialization by
C       Call SetCtq6(Iset)
C   where Iset is the desired PDF specified in the above table.
C
C   The function Ctq6Pdf (Iparton, X, Q)
C   returns the parton distribution inside the proton for parton [Iparton]
C   at [X] Bjorken_X and scale [Q] (GeV) in PDF set [Iset].
C   Iparton  is the parton label (5, 4, 3, 2, 1, 0, -1, ......, -5)
C                            for (b, c, s, d, u, g, u_bar, ..., b_bar),
C
C   For detailed information on the parameters used, e.q. quark masses,
C   QCD Lambda, ... etc.,  see info lines at the beginning of the
C   Table_Files.
C
C   These programs, as provided, are in double precision.  By removing the
C   "Implicit Double Precision" lines, they can also be run in single
C   precision.
C
C   If you have detailed questions concerning these CTEQ6 distributions,
C   or if you find problems/bugs using this package, direct inquires to
C   Pumplin@pa.msu.edu or Tung@pa.msu.edu.
C
C===========================================================================