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.
A surjective map need not be a fibration
Statement refuted
Every continuous surjection is a Serre fibration (and hence, more strongly, every continuous surjection is a Hurewicz fibration).
Facts & Assumptions
A Serre or Hurewicz fibration lifts every path with prescribed initial point, since its test class contains . Hurewicz and serre fibrations
Continuity means preimages of open sets are open. Continuity of a map of topological spaces at a point and globally
The map is a homeomorphism from onto the geometric circle. is a homeomorphism from to the unit circle
The subtraction formulas express the sine and cosine of a difference. The subtraction formulas for sine and cosine
The sine zero set is , and sine and cosine are -periodic. The zero sets of sine and cosine and the least positive common period 2 pi
The closed bounded interval is compact in its ordinary topology. A subset of with the product topology is compact exactly when it is closed and bounded, the product topology being the Euclidean metric topology
Closed subspaces of compact spaces are compact. A closed subspace of a compact space is compact, and a finite union of compact subspaces is compact
The Pythagorean identity gives for every real . Parity and the Pythagorean identity for sine and cosine
The shift identity is , with . Quarter-turn values and shifts by pi/2 and pi
Counterexample
Given: , , and the path beginning at .
Let be , so . We first verify locally the equality-of-values clause in F3 on the full real-line map Q. If , F4 and F9 give and . By F5, . F10 gives and , so integer induction in both directions gives . Since the difference cosine is one, is even and . Conversely F5's -periodicity gives whenever . Thus this clause no longer depends on the affected published inference. F3 makes Q continuous and onto; every real coset has a representative in , so q is continuous and onto. It is also a quotient map: a closed subset of is compact by F6 and F7. Its image is compact since pulling an open cover back by gives an open cover of , whose finite subcover maps to a finite cover of . The geometric circle is Hausdorff (disjoint sufficiently small Euclidean balls separate distinct points), so F8 makes closed. Thus is closed. If is closed, surjectivity gives closed; with continuity this is the quotient criterion. For the refuted statement only continuity and surjectivity are needed. The path is continuous.
Suppose a lift has . For , the equation means is an integer by the locally verified clause in step 1.1. Because and , that integer must be , so . In particular for every .
The set is a relatively open neighbourhood of . By step 2.1 its inverse image is exactly , which is not open in since every relative neighbourhood of zero contains positive numbers. This contradicts F2, so no such lift is continuous. F1 therefore excludes both Serre and Hurewicz fibrations. The failure occurs at the initial endpoint, despite the unique possible positive-time lift and the value . All spaces are nonempty and all paths were explicit; no AC is involved.
Depends on
- Hurewicz and serre fibrations
- Continuity of a map of topological spaces at a point and globally
- $[t]\mapsto(\cos 2\pi t,\sin 2\pi t)$ is a homeomorphism from $\mathbb R/\mathbb Z$ to the unit circle
- The subtraction formulas for sine and cosine
- Parity and the Pythagorean identity for sine and cosine
- The zero sets of sine and cosine and the least positive common period 2 pi
- Quarter-turn values and shifts by pi/2 and pi
- A subset of $\mathbb{R}^n$ with the product topology is compact exactly when it is closed and bounded, the product topology being the Euclidean metric topology
- A closed subspace of a compact space is compact, and a finite union of compact subspaces is compact
- In a Hausdorff space a point and a disjoint compact set, and two disjoint compact sets, have disjoint open neighbourhoods; hence every compact subset is closed, and in a compact Hausdorff space the compact subsets are exactly the closed ones
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
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Sources
- May, A Concise Course in Algebraic Topology (standard reference, not scraped)
- Hatcher, Algebraic Topology (standard reference, not scraped)