Description: The "less than or equal to" relation in the extended real numbers. (Contributed by Thierry Arnoux, 14-Mar-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xrge0le | |- <_ = ( le ` ( RR*s |`s ( 0 [,] +oo ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ovex | |- ( 0 [,] +oo ) e. _V |
|
| 2 | eqid | |- ( RR*s |`s ( 0 [,] +oo ) ) = ( RR*s |`s ( 0 [,] +oo ) ) |
|
| 3 | xrsle | |- <_ = ( le ` RR*s ) |
|
| 4 | 2 3 | ressle | |- ( ( 0 [,] +oo ) e. _V -> <_ = ( le ` ( RR*s |`s ( 0 [,] +oo ) ) ) ) |
| 5 | 1 4 | ax-mp | |- <_ = ( le ` ( RR*s |`s ( 0 [,] +oo ) ) ) |