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تسجيل مستخدم جديدMaximal independent sets, variants of chain/antichain principle and cofinal subsets without AC
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Amitayu Banerjee
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In set theory without the Axiom of Choice (AC), we observe new relations of the following statements with weak choice principles. 1. Every locally finite connected graph has a maximal independent set. 2. Every locally countable connected graph has a maximal independent set. 3. If in a partially ordered set all antichains are finite and all chains have size $aleph_{alpha}$, then the set has size $aleph_{alpha}$ if $aleph_{alpha}$ is regular. 4. Every partially ordered set has a cofinal well-founded subset. 5. If $G=(V_{G},E_{G})$ is a connected locally finite chordal graph, then there is an ordering $<$ of $V_{G}$ such that ${w < v : {w,v} in E_{G}}$ is a clique for each $vin V_{G}$.
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