A tree with a finite number of branches at each fork and with a finite number of leaves
at the end of each branch is called a finitely branching tree.
König's lemma states that a finitely branching tree is infinite iff
it has an infinite path.
This lemma is used in proofs of completeness in logic.
See also
Branch,
Fork,
Kruskal's Tree Theorem,
Tree,
Tree Leaf
This entry contributed by Alex
Sakharov (author's link)
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References
Kleene, S. C. Mathematical Logic. New York: Dover, 2002.Referenced on Wolfram|Alpha
König's Lemma
Cite this as:
Sakharov, Alex. "König's Lemma." From MathWorld--A Wolfram Web Resource, created by Eric
W. Weisstein. https://mathworld.wolfram.com/KoenigsLemma.html
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