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Mirrors > Home > MPE Home > Th. List > zfrepclf | Structured version Visualization version GIF version |
Description: An inference based on the Axiom of Replacement. Typically, 𝜑 defines a function from 𝑥 to 𝑦. (Contributed by NM, 26-Nov-1995.) |
Ref | Expression |
---|---|
zfrepclf.1 | ⊢ Ⅎ𝑥𝐴 |
zfrepclf.2 | ⊢ 𝐴 ∈ V |
zfrepclf.3 | ⊢ (𝑥 ∈ 𝐴 → ∃𝑧∀𝑦(𝜑 → 𝑦 = 𝑧)) |
Ref | Expression |
---|---|
zfrepclf | ⊢ ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | zfrepclf.2 | . 2 ⊢ 𝐴 ∈ V | |
2 | zfrepclf.1 | . . . . . 6 ⊢ Ⅎ𝑥𝐴 | |
3 | 2 | nfeq2 2966 | . . . . 5 ⊢ Ⅎ𝑥 𝑣 = 𝐴 |
4 | eleq2 2873 | . . . . . 6 ⊢ (𝑣 = 𝐴 → (𝑥 ∈ 𝑣 ↔ 𝑥 ∈ 𝐴)) | |
5 | zfrepclf.3 | . . . . . 6 ⊢ (𝑥 ∈ 𝐴 → ∃𝑧∀𝑦(𝜑 → 𝑦 = 𝑧)) | |
6 | 4, 5 | syl6bi 254 | . . . . 5 ⊢ (𝑣 = 𝐴 → (𝑥 ∈ 𝑣 → ∃𝑧∀𝑦(𝜑 → 𝑦 = 𝑧))) |
7 | 3, 6 | alrimi 2180 | . . . 4 ⊢ (𝑣 = 𝐴 → ∀𝑥(𝑥 ∈ 𝑣 → ∃𝑧∀𝑦(𝜑 → 𝑦 = 𝑧))) |
8 | nfv 1896 | . . . . 5 ⊢ Ⅎ𝑧𝜑 | |
9 | 8 | axrep5 5094 | . . . 4 ⊢ (∀𝑥(𝑥 ∈ 𝑣 → ∃𝑧∀𝑦(𝜑 → 𝑦 = 𝑧)) → ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑))) |
10 | 7, 9 | syl 17 | . . 3 ⊢ (𝑣 = 𝐴 → ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑))) |
11 | 4 | anbi1d 629 | . . . . . . 7 ⊢ (𝑣 = 𝐴 → ((𝑥 ∈ 𝑣 ∧ 𝜑) ↔ (𝑥 ∈ 𝐴 ∧ 𝜑))) |
12 | 3, 11 | exbid 2192 | . . . . . 6 ⊢ (𝑣 = 𝐴 → (∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑) ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))) |
13 | 12 | bibi2d 344 | . . . . 5 ⊢ (𝑣 = 𝐴 → ((𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑)) ↔ (𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)))) |
14 | 13 | albidv 1902 | . . . 4 ⊢ (𝑣 = 𝐴 → (∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑)) ↔ ∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)))) |
15 | 14 | exbidv 1903 | . . 3 ⊢ (𝑣 = 𝐴 → (∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝑣 ∧ 𝜑)) ↔ ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)))) |
16 | 10, 15 | mpbid 233 | . 2 ⊢ (𝑣 = 𝐴 → ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))) |
17 | 1, 16 | vtocle 3529 | 1 ⊢ ∃𝑧∀𝑦(𝑦 ∈ 𝑧 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 207 ∧ wa 396 ∀wal 1523 = wceq 1525 ∃wex 1765 ∈ wcel 2083 Ⅎwnfc 2935 Vcvv 3440 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1781 ax-4 1795 ax-5 1892 ax-6 1951 ax-7 1996 ax-8 2085 ax-9 2093 ax-10 2114 ax-11 2128 ax-12 2143 ax-ext 2771 ax-rep 5088 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 843 df-tru 1528 df-ex 1766 df-nf 1770 df-cleq 2790 df-clel 2865 df-nfc 2937 |
This theorem is referenced by: zfrep3cl 5097 zfrep4 5098 |
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