Description: The sum of two positive reals is greater than one of them. (Contributed by NM, 13-May-1996) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ltaddpr2 | |- ( C e. P. -> ( ( A +P. B ) = C -> A |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eleq1 | |- ( ( A +P. B ) = C -> ( ( A +P. B ) e. P. <-> C e. P. ) ) |
|
| 2 | dmplp | |- dom +P. = ( P. X. P. ) |
|
| 3 | 0npr | |- -. (/) e. P. |
|
| 4 | 2 3 | ndmovrcl | |- ( ( A +P. B ) e. P. -> ( A e. P. /\ B e. P. ) ) |
| 5 | 1 4 | biimtrrdi | |- ( ( A +P. B ) = C -> ( C e. P. -> ( A e. P. /\ B e. P. ) ) ) |
| 6 | ltaddpr | |- ( ( A e. P. /\ B e. P. ) -> A |
|
| 7 | breq2 | |- ( ( A +P. B ) = C -> ( A |
|
| 8 | 6 7 | imbitrid | |- ( ( A +P. B ) = C -> ( ( A e. P. /\ B e. P. ) -> A |
| 9 | 5 8 | syldc | |- ( C e. P. -> ( ( A +P. B ) = C -> A |