Description: Weak version of funex that holds without ax-rep . If the domain and codomain of a function exist, so does the function. (Contributed by Rohan Ridenour, 13-Aug-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | funexw | ⊢ ( ( Fun 𝐹 ∧ dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶 ) → 𝐹 ∈ V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xpexg | ⊢ ( ( dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶 ) → ( dom 𝐹 × ran 𝐹 ) ∈ V ) | |
2 | 1 | 3adant1 | ⊢ ( ( Fun 𝐹 ∧ dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶 ) → ( dom 𝐹 × ran 𝐹 ) ∈ V ) |
3 | funrel | ⊢ ( Fun 𝐹 → Rel 𝐹 ) | |
4 | relssdmrn | ⊢ ( Rel 𝐹 → 𝐹 ⊆ ( dom 𝐹 × ran 𝐹 ) ) | |
5 | 3 4 | syl | ⊢ ( Fun 𝐹 → 𝐹 ⊆ ( dom 𝐹 × ran 𝐹 ) ) |
6 | 5 | 3ad2ant1 | ⊢ ( ( Fun 𝐹 ∧ dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶 ) → 𝐹 ⊆ ( dom 𝐹 × ran 𝐹 ) ) |
7 | 2 6 | ssexd | ⊢ ( ( Fun 𝐹 ∧ dom 𝐹 ∈ 𝐵 ∧ ran 𝐹 ∈ 𝐶 ) → 𝐹 ∈ V ) |