Description: The second argument of a binary relation belongs to its range. (Contributed by NM, 2-Jul-2008)
Ref | Expression | ||
---|---|---|---|
Assertion | relelrn | |- ( ( Rel R /\ A R B ) -> B e. ran R ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | brrelex1 | |- ( ( Rel R /\ A R B ) -> A e. _V ) |
|
2 | brrelex2 | |- ( ( Rel R /\ A R B ) -> B e. _V ) |
|
3 | simpr | |- ( ( Rel R /\ A R B ) -> A R B ) |
|
4 | brelrng | |- ( ( A e. _V /\ B e. _V /\ A R B ) -> B e. ran R ) |
|
5 | 1 2 3 4 | syl3anc | |- ( ( Rel R /\ A R B ) -> B e. ran R ) |