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Mirrors > Home > MPE Home > Th. List > Mathboxes > bj-nnfe1 | Structured version Visualization version GIF version |
Description: See nfe1 2140. (Contributed by BJ, 12-Aug-2023.) (Proof modification is discouraged.) |
Ref | Expression |
---|---|
bj-nnfe1 | ⊢ Ⅎ'𝑥∃𝑥𝜑 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-modal4e 36182 | . 2 ⊢ (∃𝑥∃𝑥𝜑 → ∃𝑥𝜑) | |
2 | hbe1 2132 | . 2 ⊢ (∃𝑥𝜑 → ∀𝑥∃𝑥𝜑) | |
3 | df-bj-nnf 36191 | . 2 ⊢ (Ⅎ'𝑥∃𝑥𝜑 ↔ ((∃𝑥∃𝑥𝜑 → ∃𝑥𝜑) ∧ (∃𝑥𝜑 → ∀𝑥∃𝑥𝜑))) | |
4 | 1, 2, 3 | mpbir2an 710 | 1 ⊢ Ⅎ'𝑥∃𝑥𝜑 |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∀wal 1532 ∃wex 1774 Ⅎ'wnnf 36190 |
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-10 2130 ax-12 2164 |
This theorem depends on definitions: df-bi 206 df-an 396 df-ex 1775 df-bj-nnf 36191 |
This theorem is referenced by: (None) |
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