anchor.diff:  
       if (nnuc > nprot) then
          data_type = 'nuc_acid'
  +       symbols_set = nuc_acid_set
       else
          data_type = 'protein'
  +       symbols_set = protein_set
       end if
   
       string = ""
  
positive.code:              allocate(seq(nv),stat=err)
               allocate(seqs(nv,ns),stat=err)
            end if
            call fasta_string2seq(string,seq,error_code,error_string)
            if (error_code > 0) return
            seqs(:,k) = seq
            string = ""
  
negative.code:        ['A','C','G','T','U','-']
    character(len=kprot) :: protein_set='ACDEFGHIKLMNPQRSTVWY-'
    character(len=knuc)  :: nuc_acid_set='ACGTU-'
    character(len=string_size) :: symbols_set
  
  contains
  
  