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Mirrors > Home > MPE Home > Th. List > Mathboxes > bj-nnfe | Structured version Visualization version GIF version |
Description: Nonfreeness implies the equivalent of ax5e 1912. (Contributed by BJ, 28-Jul-2023.) |
Ref | Expression |
---|---|
bj-nnfe | ⊢ (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → 𝜑)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-bj-nnf 34077 | . 2 ⊢ (Ⅎ'𝑥𝜑 ↔ ((∃𝑥𝜑 → 𝜑) ∧ (𝜑 → ∀𝑥𝜑))) | |
2 | 1 | simplbi 500 | 1 ⊢ (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → 𝜑)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∀wal 1534 ∃wex 1779 Ⅎ'wnnf 34076 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem depends on definitions: df-bi 209 df-an 399 df-bj-nnf 34077 |
This theorem is referenced by: bj-nnfed 34084 bj-nnfea 34085 bj-nnfim1 34094 bj-nnfim2 34095 bj-nnf-exlim 34106 bj-19.21t 34119 bj-19.36im 34121 bj-19.42t 34123 bj-sbft 34125 |
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