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Mathbox for Glauco Siliprandi |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > pimgtmnff | Structured version Visualization version GIF version |
Description: Given a real-valued function, the preimage of an open interval, unbounded above, with lower bound -∞, is the whole domain. (Contributed by Glauco Siliprandi, 20-Dec-2024.) |
Ref | Expression |
---|---|
pimgtmnff.1 | ⊢ Ⅎ𝑥𝜑 |
pimgtmnff.2 | ⊢ Ⅎ𝑥𝐴 |
pimgtmnff.3 | ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ) |
Ref | Expression |
---|---|
pimgtmnff | ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} = 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pimgtmnff.2 | . . . 4 ⊢ Ⅎ𝑥𝐴 | |
2 | 1 | ssrab2f 43269 | . . 3 ⊢ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} ⊆ 𝐴 |
3 | 2 | a1i 11 | . 2 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} ⊆ 𝐴) |
4 | pimgtmnff.1 | . . . 4 ⊢ Ⅎ𝑥𝜑 | |
5 | simpr 485 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐴) | |
6 | pimgtmnff.3 | . . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ) | |
7 | mnflt 13036 | . . . . . . . 8 ⊢ (𝐵 ∈ ℝ → -∞ < 𝐵) | |
8 | 6, 7 | syl 17 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → -∞ < 𝐵) |
9 | 5, 8 | jca 512 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝑥 ∈ 𝐴 ∧ -∞ < 𝐵)) |
10 | rabid 3425 | . . . . . 6 ⊢ (𝑥 ∈ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} ↔ (𝑥 ∈ 𝐴 ∧ -∞ < 𝐵)) | |
11 | 9, 10 | sylibr 233 | . . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵}) |
12 | 11 | ex 413 | . . . 4 ⊢ (𝜑 → (𝑥 ∈ 𝐴 → 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵})) |
13 | 4, 12 | ralrimi 3238 | . . 3 ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵}) |
14 | nfrab1 3424 | . . . 4 ⊢ Ⅎ𝑥{𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} | |
15 | 1, 14 | dfss3f 3933 | . . 3 ⊢ (𝐴 ⊆ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵}) |
16 | 13, 15 | sylibr 233 | . 2 ⊢ (𝜑 → 𝐴 ⊆ {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵}) |
17 | 3, 16 | eqssd 3959 | 1 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ -∞ < 𝐵} = 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 = wceq 1541 Ⅎwnf 1785 ∈ wcel 2106 Ⅎwnfc 2885 ∀wral 3062 {crab 3405 ⊆ wss 3908 class class class wbr 5103 ℝcr 11046 -∞cmnf 11183 < clt 11185 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2707 ax-sep 5254 ax-nul 5261 ax-pow 5318 ax-pr 5382 ax-un 7668 ax-cnex 11103 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-clab 2714 df-cleq 2728 df-clel 2814 df-nfc 2887 df-ral 3063 df-rex 3072 df-rab 3406 df-v 3445 df-dif 3911 df-un 3913 df-in 3915 df-ss 3925 df-nul 4281 df-if 4485 df-pw 4560 df-sn 4585 df-pr 4587 df-op 4591 df-uni 4864 df-br 5104 df-opab 5166 df-xp 5637 df-pnf 11187 df-mnf 11188 df-xr 11189 df-ltxr 11190 |
This theorem is referenced by: pimgtmnf 44896 |
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