Exercise problems for Oct 8:
Ex 9.5 (3,6,7,8,9)

Exercise problems for Oct 15:
Ex 9.5 (9,10,11),
Ex 10.4 (2)
Problem 5:
Show that every infinite partially ordered set contains an infinite
ascending, an infinite descending or an infinite antichain.
(In other words, there is a sequence $(a_i)_{i \in \N}$
 such that one of the following holds:
 (a) for all $i$ : $a_i < a_{i+1}$,
 (b) for all $i$ : $a_i > a_{i+1}$,
 (c) for all $i,j$ : $i \neq j \Rightarrow a_i || a_j$.)


Exercises for Oct 22, 2024:

10.15 (1)-(4), 10.25 (3).