Metamath Proof Explorer


Theorem pprodss4v

Description: The parallel product is a subclass of ( (V X. V ) X. (V X. V ) ) . (Contributed by Scott Fenton, 11-Apr-2014) (Revised by Mario Carneiro, 19-Apr-2014) (Proof shortened by Peter Mazsa, 2-Oct-2022)

Ref Expression
Assertion pprodss4v ⊢ pprod A B ⊆ V × V × V × V

Proof

Step Hyp Ref Expression
1 df-pprod ⊢ pprod A B = A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V
2 txprel ⊢ Rel ⁡ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V
3 txpss3v ⊢ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V ⊆ V × V × V
4 3 sseli ⊢ x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x y ∈ V × V × V
5 opelxp2 ⊢ x y ∈ V × V × V → y ∈ V × V
6 4 5 syl ⊢ x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → y ∈ V × V
7 elvv ⊢ y ∈ V × V ↔ ∃ z ∃ w y = z w
8 opeq2 ⊢ y = z w → x y = x z w
9 8 eleq1d ⊢ y = z w → x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V ↔ x z w ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V
10 df-br ⊢ x A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V z w ↔ x z w ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V
11 vex ⊢ x ∈ V
12 vex ⊢ z ∈ V
13 vex ⊢ w ∈ V
14 11 12 13 brtxp ⊢ x A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V z w ↔ x A ∘ 1 st ↾ V × V z ∧ x B ∘ 2 nd ↾ V × V w
15 11 12 brco ⊢ x A ∘ 1 st ↾ V × V z ↔ ∃ y x 1 st ↾ V × V y ∧ y A z
16 vex ⊢ y ∈ V
17 16 brresi ⊢ x 1 st ↾ V × V y ↔ x ∈ V × V ∧ x 1 st y
18 17 simplbi ⊢ x 1 st ↾ V × V y → x ∈ V × V
19 18 adantr ⊢ x 1 st ↾ V × V y ∧ y A z → x ∈ V × V
20 19 exlimiv ⊢ ∃ y x 1 st ↾ V × V y ∧ y A z → x ∈ V × V
21 15 20 sylbi ⊢ x A ∘ 1 st ↾ V × V z → x ∈ V × V
22 21 adantr ⊢ x A ∘ 1 st ↾ V × V z ∧ x B ∘ 2 nd ↾ V × V w → x ∈ V × V
23 14 22 sylbi ⊢ x A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V z w → x ∈ V × V
24 10 23 sylbir ⊢ x z w ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x ∈ V × V
25 9 24 biimtrdi ⊢ y = z w → x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x ∈ V × V
26 25 exlimivv ⊢ ∃ z ∃ w y = z w → x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x ∈ V × V
27 7 26 sylbi ⊢ y ∈ V × V → x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x ∈ V × V
28 6 27 mpcom ⊢ x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x ∈ V × V
29 28 6 opelxpd ⊢ x y ∈ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V → x y ∈ V × V × V × V
30 2 29 relssi ⊢ A ∘ 1 st ↾ V × V ⊗ B ∘ 2 nd ↾ V × V ⊆ V × V × V × V
31 1 30 eqsstri ⊢ pprod A B ⊆ V × V × V × V