Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > ptfinfin | Structured version Visualization version GIF version |
Description: A point covered by a point-finite cover is only covered by finitely many elements. (Contributed by Jeff Hankins, 21-Jan-2010.) |
Ref | Expression |
---|---|
ptfinfin.1 | ⊢ 𝑋 = ∪ 𝐴 |
Ref | Expression |
---|---|
ptfinfin | ⊢ ((𝐴 ∈ PtFin ∧ 𝑃 ∈ 𝑋) → {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥} ∈ Fin) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ptfinfin.1 | . . . . 5 ⊢ 𝑋 = ∪ 𝐴 | |
2 | 1 | isptfin 22367 | . . . 4 ⊢ (𝐴 ∈ PtFin → (𝐴 ∈ PtFin ↔ ∀𝑝 ∈ 𝑋 {𝑥 ∈ 𝐴 ∣ 𝑝 ∈ 𝑥} ∈ Fin)) |
3 | 2 | ibi 270 | . . 3 ⊢ (𝐴 ∈ PtFin → ∀𝑝 ∈ 𝑋 {𝑥 ∈ 𝐴 ∣ 𝑝 ∈ 𝑥} ∈ Fin) |
4 | eleq1 2818 | . . . . . 6 ⊢ (𝑝 = 𝑃 → (𝑝 ∈ 𝑥 ↔ 𝑃 ∈ 𝑥)) | |
5 | 4 | rabbidv 3380 | . . . . 5 ⊢ (𝑝 = 𝑃 → {𝑥 ∈ 𝐴 ∣ 𝑝 ∈ 𝑥} = {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥}) |
6 | 5 | eleq1d 2815 | . . . 4 ⊢ (𝑝 = 𝑃 → ({𝑥 ∈ 𝐴 ∣ 𝑝 ∈ 𝑥} ∈ Fin ↔ {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥} ∈ Fin)) |
7 | 6 | rspccv 3524 | . . 3 ⊢ (∀𝑝 ∈ 𝑋 {𝑥 ∈ 𝐴 ∣ 𝑝 ∈ 𝑥} ∈ Fin → (𝑃 ∈ 𝑋 → {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥} ∈ Fin)) |
8 | 3, 7 | syl 17 | . 2 ⊢ (𝐴 ∈ PtFin → (𝑃 ∈ 𝑋 → {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥} ∈ Fin)) |
9 | 8 | imp 410 | 1 ⊢ ((𝐴 ∈ PtFin ∧ 𝑃 ∈ 𝑋) → {𝑥 ∈ 𝐴 ∣ 𝑃 ∈ 𝑥} ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 399 = wceq 1543 ∈ wcel 2112 ∀wral 3051 {crab 3055 ∪ cuni 4805 Fincfn 8604 PtFincptfin 22354 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1803 ax-4 1817 ax-5 1918 ax-6 1976 ax-7 2018 ax-8 2114 ax-9 2122 ax-ext 2708 |
This theorem depends on definitions: df-bi 210 df-an 400 df-tru 1546 df-ex 1788 df-sb 2073 df-clab 2715 df-cleq 2728 df-clel 2809 df-ral 3056 df-rab 3060 df-v 3400 df-in 3860 df-ss 3870 df-uni 4806 df-ptfin 22357 |
This theorem is referenced by: locfindis 22381 comppfsc 22383 |
Copyright terms: Public domain | W3C validator |