Description: The second argument of a binary relation exists. (An artifact of our ordered pair definition.) (Contributed by Mario Carneiro, 26-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | brrelexi.1 | ⊢ Rel 𝑅 | |
Assertion | brrelex2i | ⊢ ( 𝐴 𝑅 𝐵 → 𝐵 ∈ V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brrelexi.1 | ⊢ Rel 𝑅 | |
2 | brrelex2 | ⊢ ( ( Rel 𝑅 ∧ 𝐴 𝑅 𝐵 ) → 𝐵 ∈ V ) | |
3 | 1 2 | mpan | ⊢ ( 𝐴 𝑅 𝐵 → 𝐵 ∈ V ) |