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Mirrors > Home > MPE Home > Th. List > equsalvw | Structured version Visualization version GIF version |
Description: Version of equsal 2279 with two dv conditions, which requires fewer axioms. (Contributed by BJ, 31-May-2019.) |
Ref | Expression |
---|---|
equsalvw.1 | ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) |
Ref | Expression |
---|---|
equsalvw | ⊢ (∀𝑥(𝑥 = 𝑦 → 𝜑) ↔ 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 19.23v 1889 | . 2 ⊢ (∀𝑥(𝑥 = 𝑦 → 𝜓) ↔ (∃𝑥 𝑥 = 𝑦 → 𝜓)) | |
2 | equsalvw.1 | . . . 4 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | |
3 | 2 | pm5.74i 259 | . . 3 ⊢ ((𝑥 = 𝑦 → 𝜑) ↔ (𝑥 = 𝑦 → 𝜓)) |
4 | 3 | albii 1737 | . 2 ⊢ (∀𝑥(𝑥 = 𝑦 → 𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → 𝜓)) |
5 | ax6ev 1877 | . . 3 ⊢ ∃𝑥 𝑥 = 𝑦 | |
6 | 5 | a1bi 351 | . 2 ⊢ (𝜓 ↔ (∃𝑥 𝑥 = 𝑦 → 𝜓)) |
7 | 1, 4, 6 | 3bitr4i 291 | 1 ⊢ (∀𝑥(𝑥 = 𝑦 → 𝜑) ↔ 𝜓) |
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 ax-6 1875 |
This theorem depends on definitions: df-bi 196 df-ex 1696 |
This theorem is referenced by: ax13lem2 2284 reu8 3369 asymref2 5432 intirr 5433 fun11 5877 bj-dvelimdv 32027 bj-dvelimdv1 32028 undmrnresiss 36929 pm13.192 37633 |
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