Alphabeta Math
TheoremStatement: Literature-sourcedProof: AI-adaptedSession-authored (Fable 5 assisted)precheck passjudge pass (z-ai/glm-5.2)audited 2026-07-31
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.

Every paracompact Hausdorff space is normal

Statement

Every paracompact Hausdorff topological space is normal. No choice principle is used.

Facts & Assumptions

Given: A paracompact Hausdorff space XX and disjoint closed subsets E,FXE,F\subseteq X.

[L1]

Proof

technique · direct
1.1

For each xEx\in E, regularity supplies an open UU containing xx with UF=\overline U\cap F=\varnothing; therefore the family of all such UU, together with XEX\setminus E, is an open cover U\mathcal U of XX.

L1construct
2.1

Take a locally finite open cover W\mathcal W refining U\mathcal U, and set H:={WW:WE}H:=\bigcup\{W\in\mathcal W:W\cap E\ne\varnothing\}.

F1step 1.1chooseconstruct
3.1

The open set HH contains EE, because a member of W\mathcal W containing a point of EE cannot lie inside XEX\setminus E.

step 1.1step 2.1
3.2

Every member WW used in HH lies in one of the eligible UU and so has WF=\overline W\cap F=\varnothing; hence H=W\overline H=\bigcup\overline W is disjoint from FF by [L2].

step 1.1step 2.1L2
4.1

The open sets HH and XHX\setminus\overline H contain EE and FF respectively and are disjoint, so [F2] proves normality.

step 3.1step 3.2F2

Depends on

Used by

Dependency tree · next 3 levels

Direct dependencies and their dependencies through the next three levels: 56 results over 14 levels. An arrow runs from a result to what uses it, and this result sits at the bottom with a heavier outline. Click the chart to enlarge it.

Sources