def has_edge(e, f):
    """Check if an edge `e` is in a face `f`.

       Example:
       >>> e = (0, 1)
       >>> f = (1, 2, 3, 0)
       >>> has_edge(e, f)
       >>> True  # because 0, 1 are adjacent in f (first and last)
    """
    for pair in zip(f, f[1:] + (f[0],)):
        if e == pair or e == pair[::-1]:
            return True
    return False