Description: The output of the collection operation is a set if the second input is. (Contributed by Rohan Ridenour, 11-Aug-2023)
Ref | Expression | ||
---|---|---|---|
Hypothesis | collexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
Assertion | collexd | ⊢ ( 𝜑 → ( 𝐹 Coll 𝐴 ) ∈ V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | collexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
2 | df-coll | ⊢ ( 𝐹 Coll 𝐴 ) = ∪ 𝑥 ∈ 𝐴 Scott ( 𝐹 “ { 𝑥 } ) | |
3 | scottex2 | ⊢ Scott ( 𝐹 “ { 𝑥 } ) ∈ V | |
4 | 3 | a1i | ⊢ ( 𝜑 → Scott ( 𝐹 “ { 𝑥 } ) ∈ V ) |
5 | 4 | ralrimivw | ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 Scott ( 𝐹 “ { 𝑥 } ) ∈ V ) |
6 | iunexg | ⊢ ( ( 𝐴 ∈ 𝑉 ∧ ∀ 𝑥 ∈ 𝐴 Scott ( 𝐹 “ { 𝑥 } ) ∈ V ) → ∪ 𝑥 ∈ 𝐴 Scott ( 𝐹 “ { 𝑥 } ) ∈ V ) | |
7 | 1 5 6 | syl2anc | ⊢ ( 𝜑 → ∪ 𝑥 ∈ 𝐴 Scott ( 𝐹 “ { 𝑥 } ) ∈ V ) |
8 | 2 7 | eqeltrid | ⊢ ( 𝜑 → ( 𝐹 Coll 𝐴 ) ∈ V ) |