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Mirrors > Home > MPE Home > Th. List > 19.21v | Structured version Visualization version GIF version |
Description: Version of 19.21 2062 with a dv condition.
Notational convention: We sometimes suffix with "v" the label of a theorem using a distinct variable ("dv") condition instead of a non-freeness hypothesis such as Ⅎ𝑥𝜑. Conversely, we sometimes suffix with "f" the label of a theorem introducing such a non-freeness hypothesis ("f" stands for "not free in", see df-nf 1701) instead of a dv condition. For instance, 19.21v 1855 versus 19.21 2062 and vtoclf 3231 versus vtocl 3232. Note that "not free in" is less restrictive than "does not occur in." Note that the version with a dv condition is easily proved from the version with the corresponding non-freeness hypothesis, by using nfv 1830. However, the dv version can often be proved from fewer axioms. (Contributed by NM, 21-Jun-1993.) Reduce dependencies on axioms. (Revised by Wolf Lammen, 2-Jan-2020.) (Proof shortened by Wolf Lammen, 12-Jul-2020.) |
Ref | Expression |
---|---|
19.21v | ⊢ (∀𝑥(𝜑 → 𝜓) ↔ (𝜑 → ∀𝑥𝜓)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | stdpc5v 1854 | . 2 ⊢ (∀𝑥(𝜑 → 𝜓) → (𝜑 → ∀𝑥𝜓)) | |
2 | ax5e 1829 | . . . 4 ⊢ (∃𝑥𝜑 → 𝜑) | |
3 | 2 | imim1i 61 | . . 3 ⊢ ((𝜑 → ∀𝑥𝜓) → (∃𝑥𝜑 → ∀𝑥𝜓)) |
4 | 19.38 1757 | . . 3 ⊢ ((∃𝑥𝜑 → ∀𝑥𝜓) → ∀𝑥(𝜑 → 𝜓)) | |
5 | 3, 4 | syl 17 | . 2 ⊢ ((𝜑 → ∀𝑥𝜓) → ∀𝑥(𝜑 → 𝜓)) |
6 | 1, 5 | impbii 198 | 1 ⊢ (∀𝑥(𝜑 → 𝜓) ↔ (𝜑 → ∀𝑥𝜓)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 195 ∀wal 1473 ∃wex 1695 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 |
This theorem depends on definitions: df-bi 196 df-ex 1696 |
This theorem is referenced by: 19.32v 1856 pm11.53v 1893 19.12vvv 1894 pm11.53 2167 19.12vv 2168 cbval2 2267 cbvaldva 2269 sbhb 2426 2sb6 2432 r2al 2923 r3al 2924 r19.21v 2943 ceqsralt 3202 euind 3360 reu2 3361 reuind 3378 unissb 4405 dfiin2g 4489 axrep5 4704 asymref 5431 fvn0ssdmfun 6258 dff13 6416 mpt22eqb 6667 findcard3 8088 marypha1lem 8222 marypha2lem3 8226 aceq1 8823 kmlem15 8869 cotr2g 13563 bnj864 30246 bnj865 30247 bnj978 30273 bnj1176 30327 bnj1186 30329 dfon2lem8 30939 dffun10 31191 bj-ssb1 31822 bj-ssbcom3lem 31839 bj-cbval2v 31924 bj-axrep5 31980 bj-ralcom4 32062 mpt2bi123f 33141 mptbi12f 33145 elmapintrab 36901 undmrnresiss 36929 dfhe3 37089 dffrege115 37292 ntrneiiso 37409 ntrneikb 37412 pm10.541 37588 pm10.542 37589 19.21vv 37597 pm11.62 37616 2sbc6g 37638 2rexsb 39819 |
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