anchor.diff:        (crnnumxv(j),  j=1,crnapxo),       &
         (crpartID(j),  j=1,crnapxo),       &
         (crparentID(j),j=1,crnapxo),       &
  +      (crpairID(:,j),j=1,crnapxo),       &
         (crpstop(j),   j=1,crnapxo),       &
         (crxv1(j),     j=1,crnapxo),       &
         (cryv1(j),     j=1,crnapxo),       &
  
positive.code:       (nnumxv(j),  j=1,napxo),       &
        (partID(j),  j=1,napxo),       &
        (parentID(j),j=1,napxo),       &
        (pstop(j),   j=1,napxo),       &
        (xv1(j),     j=1,napxo),       &
        (yv1(j),     j=1,napxo),       &
  
negative.code:   integer :: npair_new
    npair_new = npart_new/2 + 1
  
    call alloc(crxv1,        npart_new,    zero,    "crxv1")
    call alloc(crxv2,        npart_new,    zero,    "crxv2")
    call alloc(cryv1,        npart_new,    zero,    "cryv1")
    call alloc(cryv2,        npart_new,    zero,    "cryv2")
    call alloc(crsigmv,      npart_new,    zero,    "crsigmv")
    call alloc(crdpsv,       npart_new,    zero,    "crdpsv")
    call alloc(crdpsv1,      npart_new,    zero,    "crdpsv1")
    call alloc(crejv,        npart_new,    zero,    "crejv")
    call alloc(crejfv,       npart_new,    zero,    "crejfv")
    call alloc(crnucm,       npart_new,    nucm0,   "crnucm")
    call alloc(crmtc,        npart_new,    one,     "crmtc")
    call alloc(crnaa,        npart_new,    aa0,     "crnaa")
    call alloc(crnzz,        npart_new,    zz0,     "crnzz")
    call alloc(crnqq,        npart_new,    qq0,     "crnqq")
    call alloc(crpdgid,      npart_new,    pdgid0,  "crpdgid")
    call alloc(craperv,      npart_new, 2, zero,    "craperv")
    call alloc(binrecs,      npair_new,    0,       "binrecs")
    call alloc(crbinrecs,    npair_new,    0,       "crbinrecs")
    call alloc(crnumxv,      npart_new,    0,       "crnumxv")
    call alloc(crnnumxv,     npart_new,    0,       "crnnumxv")
    call alloc(crpartID,     npart_new,    0,       "crpartID")
    call alloc(crparentID,   npart_new,    0,       "crparentID")
    call alloc(crpairID,  2, npart_new,    0,       "crpairID")
    call alloc(crpstop,      npart_new,    .false., "crpstop")
    call alloc(crllostp,     npart_new,    .false., "crllostp")
  
    crnpart_old = npart_new
  
  