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Mirrors > Home > MPE Home > Th. List > Mathboxes > superuncl | Structured version Visualization version GIF version |
Description: The class of all supersets of a class is closed under binary union. (Contributed by Richard Penner, 3-Jan-2020.) |
Ref | Expression |
---|---|
superficl.a | ⊢ 𝐴 = {𝑧 ∣ 𝐵 ⊆ 𝑧} |
Ref | Expression |
---|---|
superuncl | ⊢ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥 ∪ 𝑦) ∈ 𝐴 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | superficl.a | . 2 ⊢ 𝐴 = {𝑧 ∣ 𝐵 ⊆ 𝑧} | |
2 | vex 3203 | . . 3 ⊢ 𝑥 ∈ V | |
3 | vex 3203 | . . 3 ⊢ 𝑦 ∈ V | |
4 | 2, 3 | unex 6956 | . 2 ⊢ (𝑥 ∪ 𝑦) ∈ V |
5 | sseq2 3627 | . 2 ⊢ (𝑧 = (𝑥 ∪ 𝑦) → (𝐵 ⊆ 𝑧 ↔ 𝐵 ⊆ (𝑥 ∪ 𝑦))) | |
6 | sseq2 3627 | . 2 ⊢ (𝑧 = 𝑥 → (𝐵 ⊆ 𝑧 ↔ 𝐵 ⊆ 𝑥)) | |
7 | sseq2 3627 | . 2 ⊢ (𝑧 = 𝑦 → (𝐵 ⊆ 𝑧 ↔ 𝐵 ⊆ 𝑦)) | |
8 | ssun3 3778 | . . 3 ⊢ (𝐵 ⊆ 𝑥 → 𝐵 ⊆ (𝑥 ∪ 𝑦)) | |
9 | 8 | adantr 481 | . 2 ⊢ ((𝐵 ⊆ 𝑥 ∧ 𝐵 ⊆ 𝑦) → 𝐵 ⊆ (𝑥 ∪ 𝑦)) |
10 | 1, 4, 5, 6, 7, 9 | cllem0 37871 | 1 ⊢ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 (𝑥 ∪ 𝑦) ∈ 𝐴 |
Colors of variables: wff setvar class |
Syntax hints: = wceq 1483 ∈ wcel 1990 {cab 2608 ∀wral 2912 Vcvv 3200 ∪ cun 3572 ⊆ wss 3574 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1722 ax-4 1737 ax-5 1839 ax-6 1888 ax-7 1935 ax-8 1992 ax-9 1999 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 ax-ext 2602 ax-sep 4781 ax-nul 4789 ax-pr 4906 ax-un 6949 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-tru 1486 df-ex 1705 df-nf 1710 df-sb 1881 df-clab 2609 df-cleq 2615 df-clel 2618 df-nfc 2753 df-ral 2917 df-rex 2918 df-v 3202 df-dif 3577 df-un 3579 df-in 3581 df-ss 3588 df-nul 3916 df-sn 4178 df-pr 4180 df-uni 4437 |
This theorem is referenced by: (None) |
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