Description: "Less than or equal to" is a relation. (Contributed by FL, 2-Aug-2009) (Revised by Mario Carneiro, 28-Apr-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | lerel | |- Rel <_ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | lerelxr | |- <_ C_ ( RR* X. RR* ) |
|
| 2 | relxp | |- Rel ( RR* X. RR* ) |
|
| 3 | relss | |- ( <_ C_ ( RR* X. RR* ) -> ( Rel ( RR* X. RR* ) -> Rel <_ ) ) |
|
| 4 | 1 2 3 | mp2 | |- Rel <_ |