def hyperplane_mem(concept, plane, eta: float = 1e-12) -> bool:
    """
    Tests whether a specified atom (hyperplane) belongs to a concept (point in parameter space)
    Here we assume that membership holds if point is below the plane (ie higher values of parameter result in stricter predicate)
    """
    height = concept[1:] @ plane[:-1] + plane[-1]
    return concept[0] - height < 0