Description: Uniqueness of the middle point, expressed with point inversion. Theorem 7.18 of Schwabhauser p. 52. (Contributed by Thierry Arnoux, 30-Jul-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | mirval.p | |- P = ( Base ` G ) | |
| mirval.d | |- .- = ( dist ` G ) | ||
| mirval.i | |- I = ( Itv ` G ) | ||
| mirval.l | |- L = ( LineG ` G ) | ||
| mirval.s | |- S = ( pInvG ` G ) | ||
| mirval.g | |- ( ph -> G e. TarskiG ) | ||
| miduniq1.a | |- ( ph -> A e. P ) | ||
| miduniq1.b | |- ( ph -> B e. P ) | ||
| miduniq1.x | |- ( ph -> X e. P ) | ||
| miduniq1.e | |- ( ph -> ( ( S ` A ) ` X ) = ( ( S ` B ) ` X ) ) | ||
| Assertion | miduniq1 | |- ( ph -> A = B ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | mirval.p | |- P = ( Base ` G ) | |
| 2 | mirval.d | |- .- = ( dist ` G ) | |
| 3 | mirval.i | |- I = ( Itv ` G ) | |
| 4 | mirval.l | |- L = ( LineG ` G ) | |
| 5 | mirval.s | |- S = ( pInvG ` G ) | |
| 6 | mirval.g | |- ( ph -> G e. TarskiG ) | |
| 7 | miduniq1.a | |- ( ph -> A e. P ) | |
| 8 | miduniq1.b | |- ( ph -> B e. P ) | |
| 9 | miduniq1.x | |- ( ph -> X e. P ) | |
| 10 | miduniq1.e | |- ( ph -> ( ( S ` A ) ` X ) = ( ( S ` B ) ` X ) ) | |
| 11 | eqid | |- ( S ` A ) = ( S ` A ) | |
| 12 | 1 2 3 4 5 6 7 11 9 | mircl | |- ( ph -> ( ( S ` A ) ` X ) e. P ) | 
| 13 | eqidd | |- ( ph -> ( ( S ` A ) ` X ) = ( ( S ` A ) ` X ) ) | |
| 14 | 10 | eqcomd | |- ( ph -> ( ( S ` B ) ` X ) = ( ( S ` A ) ` X ) ) | 
| 15 | 1 2 3 4 5 6 7 8 9 12 13 14 | miduniq | |- ( ph -> A = B ) |