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Mirrors > Home > MPE Home > Th. List > nfabd | Structured version Visualization version GIF version |
Description: Bound-variable hypothesis builder for a class abstraction. Usage of this theorem is discouraged because it depends on ax-13 2365. Use the weaker nfabdw 2915 when possible. (Contributed by Mario Carneiro, 8-Oct-2016.) Avoid ax-9 2108 and ax-ext 2696. (Revised by Wolf Lammen, 23-May-2023.) (New usage is discouraged.) |
Ref | Expression |
---|---|
nfabd.1 | ⊢ Ⅎ𝑦𝜑 |
nfabd.2 | ⊢ (𝜑 → Ⅎ𝑥𝜓) |
Ref | Expression |
---|---|
nfabd | ⊢ (𝜑 → Ⅎ𝑥{𝑦 ∣ 𝜓}) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfv 1909 | . 2 ⊢ Ⅎ𝑧𝜑 | |
2 | df-clab 2703 | . . 3 ⊢ (𝑧 ∈ {𝑦 ∣ 𝜓} ↔ [𝑧 / 𝑦]𝜓) | |
3 | nfabd.1 | . . . 4 ⊢ Ⅎ𝑦𝜑 | |
4 | nfabd.2 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜓) | |
5 | 3, 4 | nfsbd 2515 | . . 3 ⊢ (𝜑 → Ⅎ𝑥[𝑧 / 𝑦]𝜓) |
6 | 2, 5 | nfxfrd 1848 | . 2 ⊢ (𝜑 → Ⅎ𝑥 𝑧 ∈ {𝑦 ∣ 𝜓}) |
7 | 1, 6 | nfcd 2883 | 1 ⊢ (𝜑 → Ⅎ𝑥{𝑦 ∣ 𝜓}) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 Ⅎwnf 1777 [wsb 2059 ∈ wcel 2098 {cab 2702 Ⅎwnfc 2875 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-10 2129 ax-11 2146 ax-12 2166 ax-13 2365 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-tru 1536 df-ex 1774 df-nf 1778 df-sb 2060 df-clab 2703 df-nfc 2877 |
This theorem is referenced by: nfabd2 2918 nfsbcd 3799 nfcsbd 3917 nfiotad 6510 nfiundg 48358 |
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