![]() |
Mathbox for Jonathan Ben-Naim |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > Mathboxes > bnj956 | Structured version Visualization version GIF version |
Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.) (New usage is discouraged.) |
Ref | Expression |
---|---|
bnj956.1 | ⊢ (𝐴 = 𝐵 → ∀𝑥 𝐴 = 𝐵) |
Ref | Expression |
---|---|
bnj956 | ⊢ (𝐴 = 𝐵 → ∪ 𝑥 ∈ 𝐴 𝐶 = ∪ 𝑥 ∈ 𝐵 𝐶) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bnj956.1 | . . . 4 ⊢ (𝐴 = 𝐵 → ∀𝑥 𝐴 = 𝐵) | |
2 | eleq2 2815 | . . . . . . 7 ⊢ (𝐴 = 𝐵 → (𝑥 ∈ 𝐴 ↔ 𝑥 ∈ 𝐵)) | |
3 | 2 | anbi1d 629 | . . . . . 6 ⊢ (𝐴 = 𝐵 → ((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ↔ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶))) |
4 | 3 | alexbii 1828 | . . . . 5 ⊢ (∀𝑥 𝐴 = 𝐵 → (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) ↔ ∃𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶))) |
5 | df-rex 3061 | . . . . 5 ⊢ (∃𝑥 ∈ 𝐴 𝑦 ∈ 𝐶 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶)) | |
6 | df-rex 3061 | . . . . 5 ⊢ (∃𝑥 ∈ 𝐵 𝑦 ∈ 𝐶 ↔ ∃𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) | |
7 | 4, 5, 6 | 3bitr4g 313 | . . . 4 ⊢ (∀𝑥 𝐴 = 𝐵 → (∃𝑥 ∈ 𝐴 𝑦 ∈ 𝐶 ↔ ∃𝑥 ∈ 𝐵 𝑦 ∈ 𝐶)) |
8 | 1, 7 | syl 17 | . . 3 ⊢ (𝐴 = 𝐵 → (∃𝑥 ∈ 𝐴 𝑦 ∈ 𝐶 ↔ ∃𝑥 ∈ 𝐵 𝑦 ∈ 𝐶)) |
9 | 8 | abbidv 2795 | . 2 ⊢ (𝐴 = 𝐵 → {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 ∈ 𝐶} = {𝑦 ∣ ∃𝑥 ∈ 𝐵 𝑦 ∈ 𝐶}) |
10 | df-iun 5003 | . 2 ⊢ ∪ 𝑥 ∈ 𝐴 𝐶 = {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑦 ∈ 𝐶} | |
11 | df-iun 5003 | . 2 ⊢ ∪ 𝑥 ∈ 𝐵 𝐶 = {𝑦 ∣ ∃𝑥 ∈ 𝐵 𝑦 ∈ 𝐶} | |
12 | 9, 10, 11 | 3eqtr4g 2791 | 1 ⊢ (𝐴 = 𝐵 → ∪ 𝑥 ∈ 𝐴 𝐶 = ∪ 𝑥 ∈ 𝐵 𝐶) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 394 ∀wal 1532 = wceq 1534 ∃wex 1774 ∈ wcel 2099 {cab 2703 ∃wrex 3060 ∪ ciun 5001 |
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-8 2101 ax-9 2109 ax-ext 2697 |
This theorem depends on definitions: df-bi 206 df-an 395 df-ex 1775 df-sb 2061 df-clab 2704 df-cleq 2718 df-clel 2803 df-rex 3061 df-iun 5003 |
This theorem is referenced by: bnj1316 34665 bnj953 34784 bnj1000 34786 bnj966 34789 |
Copyright terms: Public domain | W3C validator |