An antichain in a partial order on A is a set S ⊆ A such that no two distinct elements in S are comparable under —that is, for any distinct a, b ∈ S we have a 6b. 1 Identify all antichains S with |S|...

An antichain in a partial order on A is a set S ⊆ A such that no two distinct elements in S are comparable under —that is, for any distinct a, b ∈ S we have a 6b.

1 Identify all antichains S with |S| ≥ 2 in the partial order in Figure 8.39(a).

2 Repeat for the partial order reproduced in Figure 8.39(b)