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Mirrors > Home > MPE Home > Th. List > nd1 | Structured version Visualization version GIF version |
Description: A lemma for proving conditionless ZFC axioms. Usage of this theorem is discouraged because it depends on ax-13 2366. (Contributed by NM, 1-Jan-2002.) (New usage is discouraged.) |
Ref | Expression |
---|---|
nd1 | ⊢ (∀𝑥 𝑥 = 𝑦 → ¬ ∀𝑥 𝑦 ∈ 𝑧) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elirrv 9613 | . . 3 ⊢ ¬ 𝑧 ∈ 𝑧 | |
2 | stdpc4 2064 | . . . 4 ⊢ (∀𝑦 𝑦 ∈ 𝑧 → [𝑧 / 𝑦]𝑦 ∈ 𝑧) | |
3 | 1 | nfnth 1797 | . . . . 5 ⊢ Ⅎ𝑦 𝑧 ∈ 𝑧 |
4 | elequ1 2106 | . . . . 5 ⊢ (𝑦 = 𝑧 → (𝑦 ∈ 𝑧 ↔ 𝑧 ∈ 𝑧)) | |
5 | 3, 4 | sbie 2496 | . . . 4 ⊢ ([𝑧 / 𝑦]𝑦 ∈ 𝑧 ↔ 𝑧 ∈ 𝑧) |
6 | 2, 5 | sylib 217 | . . 3 ⊢ (∀𝑦 𝑦 ∈ 𝑧 → 𝑧 ∈ 𝑧) |
7 | 1, 6 | mto 196 | . 2 ⊢ ¬ ∀𝑦 𝑦 ∈ 𝑧 |
8 | axc11 2424 | . 2 ⊢ (∀𝑥 𝑥 = 𝑦 → (∀𝑥 𝑦 ∈ 𝑧 → ∀𝑦 𝑦 ∈ 𝑧)) | |
9 | 7, 8 | mtoi 198 | 1 ⊢ (∀𝑥 𝑥 = 𝑦 → ¬ ∀𝑥 𝑦 ∈ 𝑧) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∀wal 1532 [wsb 2060 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-12 2164 ax-13 2366 ax-ext 2698 ax-sep 5293 ax-pr 5423 ax-reg 9609 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-tru 1537 df-ex 1775 df-nf 1779 df-sb 2061 df-clab 2705 df-cleq 2719 df-clel 2805 df-ral 3057 df-rex 3066 df-v 3471 df-un 3949 df-sn 4625 df-pr 4627 |
This theorem is referenced by: axrepnd 10611 axinfndlem1 10622 axinfnd 10623 axacndlem1 10624 axacndlem2 10625 |
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