Exercise · ZW-ZORN-S-LEMMA-005 · ★☆☆ Basic
What condition must every chain satisfy to apply Zorn's lemma ?
Choose one option.
A Have a minimum. B Be a well-ordered set. C Be finite. D Have an upper bound in the set.
Show answer D. Have an upper bound in the set.
← Back to the question
Explanation The key hypothesis is that every chain has an upper bound within the partially ordered set .
Zorn's lemma is a principle equivalent to the axiom of choice stating that every nonempty partially ordered set in which every chain has an upper bound contains a maximal element.
\[\\forall P\\neq\\varnothing\\,\\Big[\\Big(\\forall C\\subseteq P\\,\\big(\\text{cadena}(C)\\Rightarrow\\\\\exists u\\in P\\,\\forall c\\in C\\,c\\le u\\big)\\Big)\\Rightarrow\\\\\exists m\\in P\\ \\text{maximal}\\Big]\]
More practice problems: zorn's lemma ZW-ZORN-S-LEMMA-001 What does Zorn's lemma state?ZW-ZORN-S-LEMMA-002 Which axiom is Zorn's lemma equivalent to?ZW-ZORN-S-LEMMA-003 What is a chain in a partially ordered set?ZW-ZORN-S-LEMMA-004 What does it mean for m to be a maximal element of P?ZW-ZORN-S-LEMMA-006 In P(\1,2\) ordered by inclusion, how many maximal elements are there?ZW-ZORN-S-LEMMA-007 Let P=\\1\,\2\,\1,2\\ ordered by inclusion. What is a maximal chain of P?ZW-ZORN-S-LEMMA-008 Let P=\1,2,3,dots\ with the divisibility order. Does P have a maximal element?ZW-ZORN-S-LEMMA-009 What is the upper bound of the chain \\1,dots,n\: n∈ℕ\ among the finite subsets of ℕ?