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Mirrors > Home > ILE Home > Th. List > ralnex | GIF version |
Description: Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.) |
Ref | Expression |
---|---|
ralnex | ⊢ (∀x ∈ A ¬ φ ↔ ¬ ∃x ∈ A φ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ral 2305 | . 2 ⊢ (∀x ∈ A ¬ φ ↔ ∀x(x ∈ A → ¬ φ)) | |
2 | alinexa 1491 | . . 3 ⊢ (∀x(x ∈ A → ¬ φ) ↔ ¬ ∃x(x ∈ A ∧ φ)) | |
3 | df-rex 2306 | . . 3 ⊢ (∃x ∈ A φ ↔ ∃x(x ∈ A ∧ φ)) | |
4 | 2, 3 | xchbinxr 607 | . 2 ⊢ (∀x(x ∈ A → ¬ φ) ↔ ¬ ∃x ∈ A φ) |
5 | 1, 4 | bitri 173 | 1 ⊢ (∀x ∈ A ¬ φ ↔ ¬ ∃x ∈ A φ) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 97 ↔ wb 98 ∀wal 1240 ∃wex 1378 ∈ wcel 1390 ∀wral 2300 ∃wrex 2301 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 ax-in1 544 ax-in2 545 ax-5 1333 ax-gen 1335 ax-ie2 1380 |
This theorem depends on definitions: df-bi 110 df-tru 1245 df-fal 1248 df-ral 2305 df-rex 2306 |
This theorem is referenced by: rexalim 2313 ralinexa 2345 nrex 2405 nrexdv 2406 uni0b 3596 iindif2m 3715 icc0r 8565 |
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