Description: Existence of a difference. (Contributed by NM, 26-May-1998)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | difexg | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 ∖ 𝐵 ) ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | difss | ⊢ ( 𝐴 ∖ 𝐵 ) ⊆ 𝐴 | |
| 2 | ssexg | ⊢ ( ( ( 𝐴 ∖ 𝐵 ) ⊆ 𝐴 ∧ 𝐴 ∈ 𝑉 ) → ( 𝐴 ∖ 𝐵 ) ∈ V ) | |
| 3 | 1 2 | mpan | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 ∖ 𝐵 ) ∈ V ) |