def has_rep(chrn, rfrom, rto, rstrand, rep_pos):
    """
    Return the names of the REP elements in the region
    Arguments:
    - `chrn`: chromosome name
    - `rfrom`: region from
    - `rto`: region to
    - `rstrand`: region strand
    - `rep_pos`: REP positions dictionary
    """
    reps = []
    for repel, repp in rep_pos.items():
        if repp[0] == chrn and repp[3] == rstrand:
            if repp[1]<rto and repp[2]>=rfrom:
                reps.append(repel)
    return reps