How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Finite strictly decreasing sequences of naturals form a tree with every finite level nonempty but no infinite branch
Statement refuted
In König's infinity lemma: an ordered finitely branching tree with a node at every level has an infinite branch, in ZF, finite branching can be replaced by arbitrary branching: every tree of finite sequences with a node at every level has an infinite branch.
Facts & Assumptions
Given: The tree conventions of Rooted trees of finite sequences, levels, branches, and finite branching, with ordered finite successor sets.
An ordered finitely branching tree with a node at every level has an infinite branch, in ZF (König's infinity lemma: an ordered finitely branching tree with a node at every level has an infinite branch, in ZF).
Counterexample
Let consist of the empty sequence and all finite strictly decreasing sequences of natural numbers. It is prefix closed. For every , the sequence is a node of length , so every finite level is nonempty.
The root has infinitely many successors, so is not finitely branching. An infinite branch would be an infinite strictly decreasing sequence of naturals, but its range would have a least element by The well-ordering principle, after which the branch would have to contain a smaller one. Thus no infinite branch exists, and the missing hypothesis relative to [L1] is exactly finite branching.
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