Description: ltaddpos without ax-mulcom . (Contributed by SN, 13-Feb-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | sn-ltaddpos | |- ( ( A e. RR /\ B e. RR ) -> ( 0 < A <-> B < ( B + A ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0re | |- 0 e. RR |
|
2 | ltadd2 | |- ( ( 0 e. RR /\ A e. RR /\ B e. RR ) -> ( 0 < A <-> ( B + 0 ) < ( B + A ) ) ) |
|
3 | 1 2 | mp3an1 | |- ( ( A e. RR /\ B e. RR ) -> ( 0 < A <-> ( B + 0 ) < ( B + A ) ) ) |
4 | readdid1 | |- ( B e. RR -> ( B + 0 ) = B ) |
|
5 | 4 | adantl | |- ( ( A e. RR /\ B e. RR ) -> ( B + 0 ) = B ) |
6 | 5 | breq1d | |- ( ( A e. RR /\ B e. RR ) -> ( ( B + 0 ) < ( B + A ) <-> B < ( B + A ) ) ) |
7 | 3 6 | bitrd | |- ( ( A e. RR /\ B e. RR ) -> ( 0 < A <-> B < ( B + A ) ) ) |