Metamath Proof Explorer


Theorem iunmapss

Description: The indexed union of set exponentiations is a subset of the set exponentiation of the indexed union. (Contributed by Glauco Siliprandi, 3-Mar-2021)

Ref Expression
Hypotheses iunmapss.x 𝑥 𝜑
iunmapss.a ( 𝜑𝐴𝑉 )
iunmapss.b ( ( 𝜑𝑥𝐴 ) → 𝐵𝑊 )
Assertion iunmapss ( 𝜑 𝑥𝐴 ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )

Proof

Step Hyp Ref Expression
1 iunmapss.x 𝑥 𝜑
2 iunmapss.a ( 𝜑𝐴𝑉 )
3 iunmapss.b ( ( 𝜑𝑥𝐴 ) → 𝐵𝑊 )
4 3 ex ( 𝜑 → ( 𝑥𝐴𝐵𝑊 ) )
5 1 4 ralrimi ( 𝜑 → ∀ 𝑥𝐴 𝐵𝑊 )
6 iunexg ( ( 𝐴𝑉 ∧ ∀ 𝑥𝐴 𝐵𝑊 ) → 𝑥𝐴 𝐵 ∈ V )
7 2 5 6 syl2anc ( 𝜑 𝑥𝐴 𝐵 ∈ V )
8 7 adantr ( ( 𝜑𝑥𝐴 ) → 𝑥𝐴 𝐵 ∈ V )
9 ssiun2 ( 𝑥𝐴𝐵 𝑥𝐴 𝐵 )
10 9 adantl ( ( 𝜑𝑥𝐴 ) → 𝐵 𝑥𝐴 𝐵 )
11 mapss ( ( 𝑥𝐴 𝐵 ∈ V ∧ 𝐵 𝑥𝐴 𝐵 ) → ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )
12 8 10 11 syl2anc ( ( 𝜑𝑥𝐴 ) → ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )
13 12 ex ( 𝜑 → ( 𝑥𝐴 → ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) ) )
14 1 13 ralrimi ( 𝜑 → ∀ 𝑥𝐴 ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )
15 nfiu1 𝑥 𝑥𝐴 𝐵
16 nfcv 𝑥m
17 nfcv 𝑥 𝐶
18 15 16 17 nfov 𝑥 ( 𝑥𝐴 𝐵m 𝐶 )
19 18 iunssf ( 𝑥𝐴 ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) ↔ ∀ 𝑥𝐴 ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )
20 14 19 sylibr ( 𝜑 𝑥𝐴 ( 𝐵m 𝐶 ) ⊆ ( 𝑥𝐴 𝐵m 𝐶 ) )