CHAP. 14] ORDERED SETS AND LATTICES 363
LATTICES
14.65. Consider the latticeLin Fig. 14-19(a).
(a) Find all sublattices with five elements. (c) Find complements ofaandb, if they exist.
(b) Find all join-irreducible elements and atoms. (d) IsLdistributive? Complemented?
Fig. 14-19
14.66. Consider the latticeMin Fig. 14-19(b).
(a) Find all join-irreducible elements.
(b) Find the atoms.
(c) Find complements ofaandb, if they exist.
(d) Express eachxinMas the join of irredundant join-irreducible elements.
(e) IsMdistributive? Complemented?
14.67. Consider the bounded latticeLin Fig. 14-20(a).
(a) Find the complements, if they exist, ofeandf.
(b) ExpressIin an irredundant join-irreducible decomposition in as many ways as possible.
(c) IsLdistributive?
(d) Describe the isomorphisms ofLwith itself.
Fig. 14-20
14.68. Consider the bounded latticeLin Fig. 14-20(b).
(a) Find the complements, if they exist, ofaandc.
(b) ExpressIin an irredundant join-irreducible decomposition in as many ways as possible.
(c) IsLdistributive?
(d) Describe the isomorphisms ofLwith itself.