Metamath Proof Explorer
Description: The composition of two sets is a set. (Contributed by SN, 7-Feb-2025)
|
|
Ref |
Expression |
|
Hypotheses |
coexd.1 |
⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) |
|
|
coexd.2 |
⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) |
|
Assertion |
coexd |
⊢ ( 𝜑 → ( 𝐴 ∘ 𝐵 ) ∈ V ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
coexd.1 |
⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) |
2 |
|
coexd.2 |
⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) |
3 |
|
coexg |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊 ) → ( 𝐴 ∘ 𝐵 ) ∈ V ) |
4 |
1 2 3
|
syl2anc |
⊢ ( 𝜑 → ( 𝐴 ∘ 𝐵 ) ∈ V ) |