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Description: The second ordered pair component of a member of a relation belongs to the range of the relation. (Contributed by NM, 17-Sep-2006)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 2ndrn |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1st2nd | ||
| 2 | simpr | ||
| 3 | 1 2 | eqeltrrd | |
| 4 | fvex | ||
| 5 | fvex | ||
| 6 | 4 5 | opelrn | |
| 7 | 3 6 | syl |