anchor.diff:    integer,    allocatable :: seqs0(:,:)
     real(kflt), allocatable :: prm(:)       ! parameters array
     real(kflt), allocatable :: fmodel(:)    ! model frequencies
  -  real(kflt), allocatable :: fdata(:)     ! empirical frequencies
  -  real(kflt), allocatable :: scores(:,:)  ! final scores
     integer, allocatable    :: seqs_table(:,:)
     ! command line parameters
     integer                    :: udata        ! data unit
  
positive.code: 
  
    !================================================ print a header
  
    if ( iproc == 0 ) then
       write(ulog,'(a)')         '#'
       write(ulog,'(a)')         '#==========================================='
  
negative.code:   use units,       only: units_initialize,units_open
    use data,        only: data_read,data_average
    use random,      only: random_initialize,random_seq
    use mcmc,        only: mcmc_compute_energy
    implicit none
    integer                 :: nvars        ! total number of variables
    integer                 :: nclasses     ! total number of classes
  