| Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > ILE Home > Th. List > infiexmid | GIF version | ||
| Description: If the intersection of any finite set and any other set is finite, excluded middle follows. (Contributed by Jim Kingdon, 5-Feb-2022.) |
| Ref | Expression |
|---|---|
| infiexmid.1 | ⊢ (𝑥 ∈ Fin → (𝑥 ∩ 𝑦) ∈ Fin) |
| Ref | Expression |
|---|---|
| infiexmid | ⊢ (𝜑 ∨ ¬ 𝜑) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dfss1 3385 | . . . . . 6 ⊢ (𝑦 ⊆ 𝑥 ↔ (𝑥 ∩ 𝑦) = 𝑦) | |
| 2 | 1 | biimpi 120 | . . . . 5 ⊢ (𝑦 ⊆ 𝑥 → (𝑥 ∩ 𝑦) = 𝑦) |
| 3 | 2 | adantl 277 | . . . 4 ⊢ ((𝑥 ∈ Fin ∧ 𝑦 ⊆ 𝑥) → (𝑥 ∩ 𝑦) = 𝑦) |
| 4 | infiexmid.1 | . . . . 5 ⊢ (𝑥 ∈ Fin → (𝑥 ∩ 𝑦) ∈ Fin) | |
| 5 | 4 | adantr 276 | . . . 4 ⊢ ((𝑥 ∈ Fin ∧ 𝑦 ⊆ 𝑥) → (𝑥 ∩ 𝑦) ∈ Fin) |
| 6 | 3, 5 | eqeltrrd 2285 | . . 3 ⊢ ((𝑥 ∈ Fin ∧ 𝑦 ⊆ 𝑥) → 𝑦 ∈ Fin) |
| 7 | 6 | gen2 1474 | . 2 ⊢ ∀𝑥∀𝑦((𝑥 ∈ Fin ∧ 𝑦 ⊆ 𝑥) → 𝑦 ∈ Fin) |
| 8 | 7 | ssfiexmid 6999 | 1 ⊢ (𝜑 ∨ ¬ 𝜑) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ∨ wo 710 = wceq 1373 ∈ wcel 2178 ∩ cin 3173 ⊆ wss 3174 Fincfn 6850 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-io 711 ax-5 1471 ax-7 1472 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-8 1528 ax-10 1529 ax-11 1530 ax-i12 1531 ax-bndl 1533 ax-4 1534 ax-17 1550 ax-i9 1554 ax-ial 1558 ax-i5r 1559 ax-13 2180 ax-14 2181 ax-ext 2189 ax-sep 4178 ax-nul 4186 ax-pow 4234 ax-pr 4269 ax-un 4498 ax-iinf 4654 |
| This theorem depends on definitions: df-bi 117 df-3an 983 df-tru 1376 df-fal 1379 df-nf 1485 df-sb 1787 df-eu 2058 df-mo 2059 df-clab 2194 df-cleq 2200 df-clel 2203 df-nfc 2339 df-ral 2491 df-rex 2492 df-rab 2495 df-v 2778 df-sbc 3006 df-dif 3176 df-un 3178 df-in 3180 df-ss 3187 df-nul 3469 df-pw 3628 df-sn 3649 df-pr 3650 df-op 3652 df-uni 3865 df-int 3900 df-br 4060 df-opab 4122 df-id 4358 df-suc 4436 df-iom 4657 df-xp 4699 df-rel 4700 df-cnv 4701 df-co 4702 df-dm 4703 df-rn 4704 df-res 4705 df-ima 4706 df-iota 5251 df-fun 5292 df-fn 5293 df-f 5294 df-f1 5295 df-fo 5296 df-f1o 5297 df-fv 5298 df-1o 6525 df-er 6643 df-en 6851 df-fin 6853 |
| This theorem is referenced by: (None) |
| Copyright terms: Public domain | W3C validator |