anchor.diff:  ! 
   ! Interface to LHAPDF library
    subroutine pdfset(parm,value, mstu11, mstp51, mstp53, mstp55, qcdl4, qcdl5, axmin, axmax, aq2min, aq2max)
  -  
  + entry pdfset_herwig(parm, value) 
     ! Double precision and integer declarations.
     implicit double precision(a-h, o-z)
     implicit integer(i-n)
  
positive.code:   xmax = xxmax(iset)
    q2min=qq2min(iset)
    q2max=qq2max(iset)
    call GetLam4M(iset,LHAMEMB,qcdl4)
    call GetLam5M(iset,LHAMEMB,qcdl5)
  
    QMZ = 91.1876D0
    alphasLHA = alphasPDFM(iset,QMZ)
  
negative.code:   if(lhaparm(17).EQ.'LHAPDF') then
       nptypepdfl = 1      ! Proton PDFs
       nflpdfl = 4
       qcdl4 = qcdlha4
       qcdl5 = qcdlha5
       if (LHASILENT .NE. 1) write(lhaprint,5159) qcdl4, qcdl5
    else
       nptypepdfl = 1      ! Proton PDFs
  