anchor.diff:         ['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
   
  
positive.code: 
      if (nnuc > nprot) then
         data_type = 'nuc_acid'
      else
         data_type = 'protein'
      end if
  
      string = ""
  
negative.code:              allocate(seq(nv),stat=err)
               allocate(seqs(nv,ns),stat=err)
            end if
            call fasta_string2seq(string,symbols_set,seq,error_code)
            if (error_code > 0) return
            seqs(:,k) = seq
            string = ""
  