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Related theorems GIF version |
| Description: If a nonempty cross product is a set, so are both of its components. |
| Ref | Expression |
|---|---|
| xpexr2 | ⊢ (((A × B) ∈ C ⋀ (A × B) ≠ ∅) → (A ∈ V ⋀ B ∈ V)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dmxp 3338 | . . . . . . 7 ⊢ (B ≠ ∅ → dom ( A × B) = A) | |
| 2 | 1 | adantl 390 | . . . . . 6 ⊢ (((A × B) ∈ C ⋀ B ≠ ∅) → dom ( A × B) = A) |
| 3 | dmexg 3364 | . . . . . . 7 ⊢ ((A × B) ∈ C → dom ( A × B) ∈ V) | |
| 4 | 3 | adantr 391 | . . . . . 6 ⊢ (((A × B) ∈ C ⋀ B ≠ ∅) → dom ( A × B) ∈ V) |
| 5 | 2, 4 | eqeltrrd 1552 | . . . . 5 ⊢ (((A × B) ∈ C ⋀ B ≠ ∅) → A ∈ V) |
| 6 | rnxp 3478 | . . . . . . 7 ⊢ (A ≠ ∅ → ran ( A × B) = B) | |
| 7 | 6 | adantl 390 | . . . . . 6 ⊢ (((A × B) ∈ C ⋀ A ≠ ∅) → ran ( A × B) = B) |
| 8 | rnexg 3365 | . . . . . . 7 ⊢ ((A × B) ∈ C → ran ( A × B) ∈ V) | |
| 9 | 8 | adantr 391 | . . . . . 6 ⊢ (((A × B) ∈ C ⋀ A ≠ ∅) → ran ( A × B) ∈ V) |
| 10 | 7, 9 | eqeltrrd 1552 | . . . . 5 ⊢ (((A × B) ∈ C ⋀ A ≠ ∅) → B ∈ V) |
| 11 | 5, 10 | anim12i 333 | . . . 4 ⊢ ((((A × B) ∈ C ⋀ B ≠ ∅) ⋀ ((A × B) ∈ C ⋀ A ≠ ∅)) → (A ∈ V ⋀ B ∈ V)) |
| 12 | 11 | anandis 514 | . . 3 ⊢ (((A × B) ∈ C ⋀ (B ≠ ∅ ⋀ A ≠ ∅)) → (A ∈ V ⋀ B ∈ V)) |
| 13 | 12 | ancom2s 489 | . 2 ⊢ (((A × B) ∈ C ⋀ (A ≠ ∅ ⋀ B ≠ ∅)) → (A ∈ V ⋀ B ∈ V)) |
| 14 | xpnz 3472 | . 2 ⊢ ((A ≠ ∅ ⋀ B ≠ ∅) ↔ (A × B) ≠ ∅) | |
| 15 | 13, 14 | sylan2br 455 | 1 ⊢ (((A × B) ∈ C ⋀ (A × B) ≠ ∅) → (A ∈ V ⋀ B ∈ V)) |
| Colors of variables: wff set class |
| Syntax hints: → wi 3 ⋀ wa 223 = wceq 958 ∈ wcel 960 ≠ wne 1588 Vcvv 1814 ∅c0 2283 × cxp 3174 dom cdm 3176 ran crn 3177 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 964 ax-gen 965 ax-8 966 ax-9 967 ax-10 968 ax-11 969 ax-12 970 ax-13 971 ax-14 972 ax-17 973 ax-4 975 ax-5o 977 ax-6o 980 ax-9o 1125 ax-10o 1142 ax-16 1212 ax-11o 1220 ax-ext 1462 ax-sep 2708 ax-pow 2748 ax-pr 2785 ax-un 2872 |
| This theorem depends on definitions: df-bi 147 df-or 224 df-an 225 df-ex 983 df-sb 1174 df-eu 1384 df-mo 1385 df-clab 1467 df-cleq 1472 df-clel 1475 df-ne 1590 df-ral 1652 df-v 1815 df-dif 2052 df-un 2053 df-in 2054 df-ss 2056 df-nul 2284 df-pw 2406 df-sn 2416 df-pr 2417 df-op 2420 df-uni 2508 df-br 2625 df-opab 2672 df-xp 3190 df-rel 3191 df-cnv 3192 df-dm 3194 df-rn 3195 |