Pyrrolizine compounds having the formula ,or pharmaceutically-acceptable salts thereof, are effective in treating inflammatory or immune diseases, where A is a four- to seven-membered saturated ring, K is O or S, and R1, R2, R3 n, and M are defined in the specification. The radar reflector before deployment can be stored compactly, packed up into the minimum possible volume. The linear feedback shift register and the signature register have the same shift frequency that is greater than a frequency at which a seed vector is loaded into the seed register.