def conflateable(seg1, seg2, segment_pairs):
    """
    Return True iff seg1 and seg2 are exactly one of the segment pairs
    in segment_pairs (ignoring ordering of either).

    seg1 and seg2 will never be identical in the input.

    Parameters
    ----------

    seg1, seg2: Segment
        Two segments on which minimal pairs might hinge.
    segment_pairs: List
        list of length-2 tuples of str

    """
    for segment_pair in segment_pairs:
        seg_set = set(segment_pair)
        if seg1 in seg_set and seg2 in seg_set:
            return True
    return False