Description: The second argument of a binary relation belongs to its range. (Contributed by NM, 28-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | releldm.1 | ⊢ Rel 𝑅 | |
Assertion | relelrni | ⊢ ( 𝐴 𝑅 𝐵 → 𝐵 ∈ ran 𝑅 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | releldm.1 | ⊢ Rel 𝑅 | |
2 | relelrn | ⊢ ( ( Rel 𝑅 ∧ 𝐴 𝑅 𝐵 ) → 𝐵 ∈ ran 𝑅 ) | |
3 | 1 2 | mpan | ⊢ ( 𝐴 𝑅 𝐵 → 𝐵 ∈ ran 𝑅 ) |