cn equalitytransitive `EQ A C /\ EQ B C ==> EQ A B` cn congruencetransitive `EE P Q B C /\ EE P Q D E ==> EE B C D E` cn equalityreflexive `EQ A A` cn congruencereflexive `EE A B A B` cn equalityreverse `EE A B B A` cn sumofparts `EE A B a b /\ EE B C b c /\ BE A B C /\ BE a b c ==> EE A C a c` cn stability `~(NE A B) ==> EQ A B` cn equalitysub `EQ D A /\ BE A B C ==> BE D B C` axiom betweennessidentity `~(BE A B A)` axiom betweennesssymmetry `BE A B C ==> BE C B A` axiom innertransitivity `BE A B D /\ BE B C D ==> BE A B C` axiom connectivity `BE A B D /\ BE A C D /\ ~(BE A B C) /\ ~(BE A C B) ==> EQ B C` axiom nocollapse `NE A B /\ EE A B C D ==> NE C D` axiom 5-line `EE B C b c /\ EE A D a d /\ EE B D b d /\ BE A B C /\ BE a b c /\ EE A B a b ==> EE D C d c` postulate Pasch-inner `BE A P C /\ BE B Q C /\ NC A C B ==> ?X. BE A X Q /\ BE B X P` postulate Pasch-outer `BE A P C /\ BE B C Q /\ NC B Q A ==> ?X. BE A X Q /\ BE B P X` postulate Euclid2 `NE A B ==> ?X. BE A B X` postulate Euclid3 `NE A B ==> ?X. CI X A A B` postulate line-circle `CI K C P Q /\ IC B K /\ NE A B ==> ?X Y. CO A B X /\ BE A B Y /\ ON X K /\ ON Y K /\ BE X B Y` postulate circle-circle `CI J C R S /\ IC P J /\ OC Q J /\ CI K D F G /\ ON P K /\ ON Q K ==> ?X. ON X J /\ ON X K` postulate Euclid5 `BE r t s /\ BE p t q /\ BE r a q /\ EE p t q t /\ EE t r t s /\ NC p q s ==> ?X. BE p a X /\ BE s q X` axiom circle-center-radius `CI J A B C /\ ON P J ==> EE A P B C` axiom congruentequal `TC A B C a b c ==> ET A B C a b c` axiom ETpermutation `ET A B C a b c ==> ET A B C b c a /\ ET A B C a c b /\ ET A B C b a c /\ ET A B C c b a /\ ET A B C c a b` axiom ETsymmetric `ET A B C a b c ==> ET a b c A B C` axiom EFpermutation `EF A B C D a b c d ==> EF A B C D b c d a /\ EF A B C D d c b a /\ EF A B C D c d a b /\ EF A B C D b a d c /\ EF A B C D d a b c /\ EF A B C D c b a d /\ EF A B C D a d c b` axiom halvesofequals `ET A B C B C D /\ OS A B C D /\ ET a b c b c d /\ OS a b c d /\ EF A B D C a b d c ==> ET A B C a b c` axiom EFsymmetric `EF A B C D a b c d ==> EF a b c d A B C D` axiom EFtransitive `EF A B C D a b c d /\ EF a b c d P Q R S ==> EF A B C D P Q R S` axiom ETtransitive `ET A B C a b c /\ ET a b c P Q R ==> ET A B C P Q R` axiom cutoff1 `BE A B C /\ BE a b c /\ BE E D C /\ BE e d c /\ ET B C D b c d /\ ET A C E a c e ==> EF A B D E a b d e` axiom cutoff2 `BE B C D /\ BE b c d /\ ET C D E c d e /\ EF A B D E a b d e ==> EF A B C E a b c e` axiom paste1 `BE A B C /\ BE a b c /\ BE E D C /\ BE e d c /\ ET B C D b c d /\ EF A B D E a b d e ==> ET A C E a c e` axiom deZolt1 `BE B E D ==> ~(ET D B C E B C)` axiom deZolt2 `TR A B C /\ BE B E A /\ BE B F C ==> ~(ET A B C E B F)` axiom paste2 `BE B C D /\ BE b c d /\ ET C D E c d e /\ EF A B C E a b c e /\ BE A M D /\ BE B M E /\ BE a m d /\ BE b m e ==> EF A B D E a b d e` axiom paste3 `ET A B C a b c /\ ET A B D a b d /\ BE C M D /\ (BE A M B \/ EQ A M \/ EQ M B) /\ BE c m d /\ (BE a m b \/ EQ a m \/ EQ m b) ==> EF A C B D a c b d` axiom paste4 `EF A B m D F K H G /\ EF D B e C G H M L /\ BE A P C /\ BE B P D /\ BE K H M /\ BE F G L /\ BE B m D /\ BE B e C /\ BE F J M /\ BE K J L ==> EF A B C D F K M L` lemma equalitysymmetric `EQ B A ==> EQ A B` equalitysymmetric.prf lemma inequalitysymmetric `NE A B ==> NE B A` inequalitysymmetric.prf lemma congruencesymmetric `EE B C A D ==> EE A D B C` congruencesymmetric.prf lemma congruencetransitive `EE A B C D /\ EE C D E F ==> EE A B E F` congruencetransitive.prf lemma 3.6a `BE A B C /\ BE A C D ==> BE B C D` 3.6a.prf lemma betweennotequal `BE A B C ==> NE B C /\ NE A B /\ NE A C` betweennotequal.prf lemma extensionunique `BE A B E /\ BE A B F /\ EE B E B F ==> EQ E F` extensionunique.prf lemma doublereverse `EE A B C D ==> EE D C B A /\ EE B A D C` doublereverse.prf lemma congruenceflip `EE A B C D ==> EE B A D C /\ EE B A C D /\ EE A B D C` congruenceflip.prf lemma localextension `NE A B /\ NE B Q ==> ?X. BE A B X /\ EE B X B Q` localextension.prf lemma betweennesspreserved `EE A B a b /\ EE A C a c /\ EE B C b c /\ BE A B C ==> BE a b c` betweennesspreserved.prf lemma differenceofparts `EE A B a b /\ EE A C a c /\ BE A B C /\ BE a b c ==> EE B C b c` differenceofparts.prf lemma 3.7a `BE A B C /\ BE B C D ==> BE A C D` 3.7a.prf lemma 3.5b `BE A B D /\ BE B C D ==> BE A C D` 3.5b.prf lemma 3.6b `BE A B C /\ BE A C D ==> BE A B D` 3.6b.prf lemma 3.7b `BE A B C /\ BE B C D ==> BE A B D` 3.7b.prf lemma partnotequalwhole `BE A B C ==> ~(EE A B A C)` partnotequalwhole.prf lemma NCdistinct `NC A B C ==> NE A B /\ NE B C /\ NE A C /\ NE B A /\ NE C B /\ NE C A` NCdistinct.prf proposition 01 `NE A B ==> ?X. EL A B X /\ TR A B X` Prop01.prf proposition 02 `NE A B /\ NE B C ==> ?X. EE A X B C` Prop02.prf lemma extension `NE A B /\ NE P Q ==> ?X. BE A B X /\ EE B X P Q` extension.prf lemma lessthancongruence2 `LT A B C D /\ EE A B E F ==> LT E F C D` lessthancongruence2.prf lemma lessthancongruence `LT A B C D /\ EE C D E F ==> LT A B E F` lessthancongruence.prf lemma outerconnectivity `BE A B C /\ BE A B D /\ ~(BE B C D) /\ ~(BE B D C) ==> EQ C D` outerconnectivity.prf lemma trichotomy1 `~(LT A B C D) /\ ~(LT C D A B) /\ NE A B /\ NE C D ==> EE A B C D` trichotomy1.prf lemma interior5 `BE A B C /\ BE a b c /\ EE A B a b /\ EE B C b c /\ EE A D a d /\ EE C D c d ==> EE B D b d` interior5.prf lemma collinear1 `CO A B C ==> CO B A C` collinear1.prf lemma collinear2 `CO A B C ==> CO B C A` collinear2.prf lemma collinearorder `CO A B C ==> CO B A C /\ CO B C A /\ CO C A B /\ CO A C B /\ CO C B A` collinearorder.prf lemma NCorder `NC A B C ==> NC B A C /\ NC B C A /\ NC C A B /\ NC A C B /\ NC C B A` NCorder.prf lemma collinear4 `CO A B C /\ CO A B D /\ NE A B ==> CO B C D` collinear4.prf lemma collinear5 `NE A B /\ CO A B C /\ CO A B D /\ CO A B E ==> CO C D E` collinear5.prf lemma NChelper `NC A B C /\ CO A B P /\ CO A B Q /\ NE P Q ==> NC P Q C` NChelper.prf lemma fiveline `CO A B C /\ EE A B a b /\ EE B C b c /\ EE A D a d /\ EE C D c d /\ EE A C a c /\ NE A C ==> EE B D b d` fiveline.prf lemma twolines `CU A B C D E /\ CU A B C D F /\ NC B C D ==> EQ E F` twolines.prf lemma ray2 `RA A B C ==> NE A B` ray2.prf lemma ray `RA A B P /\ NE P B /\ ~(BE A P B) ==> BE A B P` ray.prf lemma ray1 `RA A B P ==> (BE A P B \/ EQ B P \/ BE A B P)` ray1.prf lemma ray3 `RA B C D /\ RA B C V ==> RA B D V` ray3.prf lemma raystrict `RA A B C ==> NE A C` raystrict.prf lemma ray4 `(BE A E B \/ EQ E B \/ BE A B E) /\ NE A B ==> RA A B E` ray4.prf lemma ray5 `RA A B C ==> RA A C B` ray5.prf lemma rayimpliescollinear `RA A B C ==> CO A B C` rayimpliescollinear.prf lemma tworays `RA A B C /\ RA B A C ==> BE A C B` tworays.prf lemma twolines2 `NE A B /\ NE C D /\ CO P A B /\ CO P C D /\ CO Q A B /\ CO Q C D /\ ~(CO A C D /\ CO B C D) ==> EQ P Q` twolines2.prf lemma supplements `EA A B C a b c /\ SU A B C D F /\ SU a b c d f ==> EA D B F d b f` supplements.prf lemma supplementsymmetric `SU A B C E D ==> SU D B E C A` supplementsymmetric.prf lemma collinearitypreserved `CO A B C /\ EE A B a b /\ EE A C a c /\ EE B C b c ==> CO a b c` collinearitypreserved.prf lemma trichotomy2 `LT A B C D ==> ~(LT C D A B)` trichotomy2.prf lemma lessthannotequal `LT A B C D ==> NE A B /\ NE C D` lessthannotequal.prf lemma layoff `NE A B /\ NE C D ==> ?X. RA A B X /\ EE A X C D` layoff.prf lemma layoffunique `RA A B C /\ RA A B D /\ EE A C A D ==> EQ C D` layoffunique.prf lemma lessthanbetween `LT A B A C /\ RA A B C ==> BE A B C` lessthanbetween.prf lemma lessthantransitive `LT A B C D /\ LT C D E F ==> LT A B E F` lessthantransitive.prf lemma lessthanadditive `LT A B C D /\ BE A B E /\ BE C D F /\ EE B E D F ==> LT A E C F` lessthanadditive.prf lemma subtractequals `BE A B C /\ BE A D E /\ EE B C D E /\ BE A C E ==> BE A B D` subtractequals.prf lemma crossbar `TR A B C /\ BE A E C /\ RA B A U /\ RA B C V ==> ?X. RA B E X /\ BE U X V` crossbar.prf lemma ABCequalsCBA `NC A B C ==> EA A B C C B A` ABCequalsCBA.prf lemma equalanglessymmetric `EA A B C a b c ==> EA a b c A B C` equalanglessymmetric.prf lemma angledistinct `EA A B C a b c ==> NE A B /\ NE B C /\ NE A C /\ NE a b /\ NE b c /\ NE a c` angledistinct.prf lemma 4.19 `BE A D B /\ EE A C A D /\ EE B D B C ==> EQ C D` 4.19.prf lemma collinearbetween `CO A E B /\ CO C F D /\ NE A B /\ NE C D /\ NE A E /\ NE F D /\ ~(ME A B C D) /\ BE A H D /\ CO E F H ==> BE E H F` collinearbetween.prf lemma 9.5a `OS P A B C /\ BE R P Q /\ NC R Q C /\ CO A B R ==> OS Q A B C` 9.5a.prf lemma 9.5b `OS P A B C /\ BE R Q P /\ NC C P R /\ CO A B R ==> OS Q A B C` 9.5b.prf lemma 9.5 `OS P A B C /\ RA R Q P /\ CO A B R ==> OS Q A B C` 9.5.prf lemma samesidereflexive `NC A B P ==> SS P P A B` samesidereflexive.prf lemma samesidesymmetric `SS P Q A B ==> SS Q P A B /\ SS P Q B A /\ SS Q P B A` samesidesymmetric.prf lemma oppositesidesymmetric `OS P A B Q ==> OS Q A B P` oppositesidesymmetric.prf lemma oppositesideflip `OS P A B Q ==> OS P B A Q` oppositesideflip.prf lemma samesidecollinear `SS P Q A B /\ CO A B C /\ NE A C ==> SS P Q A C` samesidecollinear.prf lemma equalanglesNC `EA A B C a b c ==> NC a b c` equalanglesNC.prf lemma ondiameter `CI K F P Q /\ EE F D P Q /\ EE F M P Q /\ BE D F M /\ BE D N M ==> IC N K` ondiameter.prf proposition 03 `LT C D A B /\ EE E F A B ==> ?X. BE E X F /\ EE E X C D` Prop03.prf proposition 04 `EE A B a b /\ EE A C a c /\ EA B A C b a c ==> EE B C b c /\ EA A B C a b c /\ EA A C B a c b` Prop04.prf lemma equalangleshelper `EA A B C a b c /\ RA b a p /\ RA b c q ==> EA A B C p b q` equalangleshelper.prf lemma equalanglestransitive `EA A B C D E F /\ EA D E F P Q R ==> EA A B C P Q R` equalanglestransitive.prf lemma equalanglesreflexive `NC A B C ==> EA A B C A B C` equalanglesreflexive.prf lemma equalanglesflip `EA A B C D E F ==> EA C B A F E D` equalanglesflip.prf lemma supplements2 `RT A B C P Q R /\ EA A B C J K L /\ RT J K L D E F ==> EA P Q R D E F /\ EA D E F P Q R` supplements2.prf lemma RTsymmetric `RT A B C D E F ==> RT D E F A B C` RTsymmetric.prf lemma RTcongruence `RT A B C D E F /\ EA A B C P Q R ==> RT P Q R D E F` RTcongruence.prf lemma midpointunique `MI A B C /\ MI A D C ==> EQ B D` midpointunique.prf lemma rightangleNC `RR A B C ==> NC A B C` rightangleNC.prf lemma 8.2 `RR A B C ==> RR C B A` 8.2.prf lemma rightreverse `RR A B C /\ BE A B D /\ EE A B B D ==> EE A C D C` rightreverse.prf lemma 8.3 `RR A B C /\ RA B C D ==> RR A B D` 8.3.prf lemma equaltorightisright `RR A B C /\ EA a b c A B C ==> RR a b c` equaltorightisright.prf lemma altitudebisectsbase `BE A M B /\ EE A P B P /\ RR A M P ==> MI A M B` altitudebisectsbase.prf lemma collinearright `RR A B D /\ CO A B C /\ NE C B ==> RR C B D` collinearright.prf lemma droppedperpendicularunique `RR A M P /\ RR A J P /\ CO A M J ==> EQ M J` droppedperpendicularunique.prf lemma 8.7 `RR C B A ==> ~(RR A C B)` 8.7.prf lemma angleorderrespectscongruence `AO A B C D E F /\ EA P Q R D E F ==> AO A B C P Q R` angleorderrespectscongruence.prf lemma angleordertransitive `AO A B C D E F /\ AO D E F P Q R ==> AO A B C P Q R` angleordertransitive.prf lemma angleorderrespectscongruence2 `AO A B C D E F /\ EA a b c A B C ==> AO a b c D E F` angleorderrespectscongruence2.prf proposition 15 `BE A E B /\ BE C E D /\ NC A E C ==> EA A E C D E B /\ EA C E B A E D` Prop15.prf lemma supplementinequality `SU A B C D F /\ SU a b c d f /\ AO a b c A B C ==> AO D B F d b f` supplementinequality.prf proposition 05 `IS A B C ==> EA A B C A C B` Prop05.prf proposition 05b `IS A B C /\ BE A B F /\ BE A C G ==> EA C B F B C G` Prop05b.prf proposition 10 `NE A B ==> ?X. BE A X B /\ EE X A X B` Prop10.prf lemma planeseparation `SS C D A B /\ OS D A B E ==> OS C A B E` planeseparation.prf lemma samesidetransitive `SS P Q A B /\ SS Q R A B ==> SS P R A B` samesidetransitive.prf lemma samesideflip `SS P Q A B ==> SS P Q B A` samesideflip.prf lemma samenotopposite `SS A B C D ==> ~(OS A C D B)` samenotopposite.prf lemma sameside2 `SS E F A C /\ CO A B C /\ RA B F G ==> SS E G A C` sameside2.prf proposition 12 `NE A B /\ NC A B C ==> ?X. PA C X A B X` Prop12.prf proposition 13 `BE D B C /\ NC A B C ==> RT C B A A B D` Prop13.prf proposition 07 `NE A B /\ EE C A D A /\ EE C B D B /\ SS C D A B ==> EQ C D` Prop07.prf lemma crossbar2 `AO H G A H G P /\ SS A P G H /\ RA G H S /\ RA G P T ==> ?X. BE T X S /\ RA G A X` crossbar2.prf lemma angletrichotomy `AO A B C D E F ==> ~(AO D E F A B C)` angletrichotomy.prf proposition 06a `TR A B C /\ EA A B C A C B ==> ~(LT A C A B)` Prop06a.prf proposition 06 `TR A B C /\ EA A B C A C B ==> EE A B A C` Prop06.prf proposition 08 `TR A B C /\ TR D E F /\ EE A B D E /\ EE A C D F /\ EE B C E F ==> EA B A C E D F /\ EA C B A F E D /\ EA A C B D F E` Prop08.prf proposition 09 `NC B A C ==> ?X. EA B A X X A C /\ IA B A C X` Prop09.prf proposition 11 `BE A C B ==> ?X. RR A C X` Prop11.prf lemma pointreflectionisometry `MI A B C /\ MI P B Q /\ NE A P ==> EE A P C Q` pointreflectionisometry.prf lemma rightreflection `RR A B C /\ MI A E a /\ MI B E b /\ MI C E c ==> RR a b c` rightreflection.prf lemma notperp `BE A C B /\ NC A B P ==> ?X. NC A B X /\ SS X P A B /\ ~(RR A C X)` notperp.prf proposition 11B `BE A C B /\ NC A B P ==> ?X. RR A C X /\ OS X A B P` Prop11B.prf lemma linereflectionisometry `RR B A C /\ RR A B D /\ BE C A E /\ BE D B F /\ EE A C A E /\ EE B D B F ==> EE C D E F` linereflectionisometry.prf lemma 10.12 `RR A B C /\ RR A B H /\ EE B C B H ==> EE A C A H` 10.12.prf lemma erectedperpendicularunique `RR A B C /\ RR A B E /\ SS C E A B ==> RA B C E` erectedperpendicularunique.prf proposition 14 `RT A B C D B E /\ RA B C D /\ OS E D B A ==> SU A B C D E /\ BE A B E` Prop14.prf proposition 16 `TR A B C /\ BE B C D ==> AO B A C A C D /\ AO C B A A C D` Prop16.prf proposition 17 `TR A B C ==> ?X Y Z. AS A B C B C A X Y Z` Prop17.prf proposition 18 `TR A B C /\ LT A B A C ==> AO B C A A B C` Prop18.prf proposition 19 `TR A B C /\ AO B C A A B C ==> LT A B A C` Prop19.prf proposition 20 `TR A B C ==> TG B A A C B C` Prop20.prf lemma together `TG A a B b C c /\ EE D F A a /\ EE F G B b /\ BE D F G /\ EE P Q C c ==> LT P Q D G /\ NE A a /\ NE B b /\ NE C c` together.prf lemma together2 `TG A a C c B b /\ EE F G B b /\ RA F G M /\ EE F M A a /\ RA G F N /\ EE G N C c ==> RA M F N` together2.prf lemma TGsymmetric `TG A a B b C c ==> TG B b A a C c` TGsymmetric.prf lemma TGflip `TG A a B b C c ==> TG a A B b C c /\ TG A a B b c C` TGflip.prf lemma 21helper `TG B A A E B E /\ BE A E C ==> TT B A A C B E E C` 21helper.prf lemma TTorder `TT A B C D E F G H ==> TT C D A B E F G H` TTorder.prf lemma TTflip `TT A B C D E F G H ==> TT B A D C E F G H` TTflip.prf lemma TTtransitive `TT A B C D E F G H /\ TT E F G H P Q R S ==> TT A B C D P Q R S` TTtransitive.prf lemma TTflip2 `TT A B C D E F G H ==> TT A B C D H G F E` TTflip2.prf proposition 21 `TR A B C /\ BE A E C /\ BE B D E ==> TT B A A C B D D C /\ AO B A C B D C` Prop21.prf proposition 22 `TG A a B b C c /\ TG A a C c B b /\ TG B b C c A a /\ NE F E ==> ?X Y. EE F X B b /\ EE F Y A a /\ EE X Y C c /\ RA F E X /\ TR F X Y` Prop22.prf lemma Euclid4 `RR A B C /\ RR a b c ==> EA A B C a b c` Euclid4.prf lemma legsmallerhypotenuse `RR A B C ==> LT A B A C /\ LT B C A C` legsmallerhypotenuse.prf proposition 23 `NE A B /\ NC D C E ==> ?X Y. RA A B Y /\ EA X A Y D C E` Prop23.prf proposition 23B `NE A B /\ NC D C E /\ NC A B P ==> ?X Y. RA A B Y /\ EA X A Y D C E /\ OS X A B P` Prop23B.prf proposition 23C `NE A B /\ NC D C E /\ NC A B P ==> ?X Y. RA A B Y /\ EA X A Y D C E /\ SS X P A B` Prop23C.prf proposition 24 `TR A B C /\ TR D E F /\ EE A B D E /\ EE A C D F /\ AO E D F B A C ==> LT E F B C` Prop24.prf lemma angletrichotomy2 `NC A B C /\ NC D E F /\ ~(EA A B C D E F) /\ ~(AO D E F A B C) ==> AO A B C D E F` angletrichotomy2.prf proposition 25 `TR A B C /\ TR D E F /\ EE A B D E /\ EE A C D F /\ LT E F B C ==> AO E D F B A C` Prop25.prf proposition 26A `TR A B C /\ TR D E F /\ EA A B C D E F /\ EA B C A E F D /\ EE B C E F ==> EE A B D E /\ EE A C D F /\ EA B A C E D F` Prop26A.prf lemma 26helper `TR A B C /\ EA A B C D E F /\ EA B C A E F D /\ EE A B D E ==> ~(LT E F B C)` 26helper.prf proposition 26B `TR A B C /\ TR D E F /\ EA A B C D E F /\ EA B C A E F D /\ EE A B D E ==> EE B C E F /\ EE A C D F /\ EA B A C E D F` Prop26B.prf lemma parallelsymmetric `PR A B C D ==> PR C D A B` parallelsymmetric.prf lemma paralleldef2A `TP A B C D ==> PR A B C D` paralleldef2A.prf lemma parallelcollinear1 `TP A B c d /\ BE C c d ==> TP A B C d` parallelcollinear1.prf lemma tarskiparallelflip `TP A B C D ==> TP B A C D /\ TP A B D C /\ TP B A D C` tarskiparallelflip.prf lemma parallelcollinear2 `TP A B c d /\ BE c C d ==> TP A B C d` parallelcollinear2.prf lemma parallelcollinear `TP A B c d /\ CO c d C /\ NE C d ==> TP A B C d` parallelcollinear.prf lemma paralleldef2B `PR A B C D ==> TP A B C D` paralleldef2B.prf lemma parallelflip `PR A B C D ==> PR B A C D /\ PR A B D C /\ PR B A D C` parallelflip.prf lemma collinearparallel `PR A B c d /\ CO c d C /\ NE C d ==> PR A B C d` collinearparallel.prf lemma parallelNC `PR A B C D ==> NC A B C /\ NC A C D /\ NC B C D /\ NC A B D` parallelNC.prf lemma collinearparallel2 `PR A B C D /\ CO C D E /\ CO C D F /\ NE E F ==> PR A B E F` collinearparallel2.prf proposition 27 `BE A E B /\ BE C F D /\ EA A E F E F D /\ OS A E F D ==> PR A B C D` Prop27.prf proposition 27B `EA A E F E F D /\ OS A E F D ==> PR A E F D` Prop27B.prf proposition 28A `BE A G B /\ BE C H D /\ BE E G H /\ EA E G B G H D /\ SS B D G H ==> PR A B C D` Prop28A.prf proposition 28B `BE A G B /\ BE C H D /\ RT B G H G H D /\ SS B D G H ==> PR A B C D` Prop28B.prf proposition 28C `RT B G H G H D /\ SS B D G H ==> PR G B H D` Prop28C.prf proposition 28D `BE E G H /\ EA E G B G H D /\ SS B D G H ==> PR G B H D` Prop28D.prf proposition 31 `BE B D C /\ NC B C A ==> ?X Y Z. BE X A Y /\ EA Y A D A D B /\ EA Y A D B D A /\ EA D A Y B D A /\ EA X A D A D C /\ EA X A D C D A /\ EA D A X C D A /\ PR X Y B C /\ EE X A D C /\ EE A Y B D /\ EE A Z Z D /\ EE X Z Z C /\ EE B Z Z Y /\ BE X Z C /\ BE B Z Y /\ BE A Z D` Prop31.prf proposition 31short `BE B D C /\ NC B C A ==> ?X Y Z. BE X A Y /\ EA X A D A D C /\ PR X Y B C /\ BE X Z C /\ BE A Z D` Prop31short.prf proposition 29 `PR A B C D /\ BE A G B /\ BE C H D /\ BE E G H /\ OS A G H D ==> EA A G H G H D /\ EA E G B G H D /\ RT B G H G H D` Prop29.prf proposition 29B `PR A G H D /\ OS A G H D ==> EA A G H G H D` Prop29B.prf proposition 29C `PR G B H D /\ SS B D G H /\ BE E G H ==> EA E G B G H D /\ RT B G H G H D` Prop29C.prf lemma crossimpliesopposite `CR A B C D /\ NC A C D ==> OS A C D B /\ OS A D C B /\ OS B C D A /\ OS B D C A` crossimpliesopposite.prf lemma crisscross `PR A C B D /\ ~(CR A B C D) ==> CR A D B C` crisscross.prf proposition 30A `PR A B E F /\ PR C D E F /\ BE G H K /\ BE A G B /\ BE E H F /\ BE C K D /\ OS A G H F /\ OS F H K C ==> PR A B C D` Prop30A.prf lemma 30helper `PR A B E F /\ BE A G B /\ BE E H F /\ ~(CR A F G H) ==> CR A E G H` 30helper.prf proposition 30 `PR A B E F /\ PR C D E F /\ BE G H K /\ CO A B G /\ CO E F H /\ CO C D K /\ NE A G /\ NE E H /\ NE C K ==> PR A B C D` Prop30.prf proposition 30B `PR A B E F /\ PR C D E F /\ BE G K H /\ BE A G B /\ BE E H F /\ BE C K D /\ OS A G H F /\ OS C K H F ==> PR A B C D` Prop30B.prf proposition 32 `TR A B C /\ BE B C D ==> AS C A B A B C A C D` Prop32.prf proposition 33 `PR A B C D /\ EE A B C D /\ BE A M D /\ BE B M C ==> PR A C B D /\ EE A C B D` Prop33.prf lemma diagonalsmeet `PG A B C D ==> ?X. BE A X C /\ BE B X D` diagonalsmeet.prf lemma TCreflexive `TR A B C ==> TC A B C A B C` TCreflexive.prf lemma EFreflexive `BE a p c /\ BE b p d /\ NC a b c ==> EF a b c d a b c d` EFreflexive.prf lemma parallelPasch `PG A B C D /\ BE A D E ==> ?X. BE B X E /\ BE C X D` parallelPasch.prf lemma parallelbetween `BE H B K /\ PR M B H L /\ CO L M K ==> BE L M K` parallelbetween.prf proposition 34 `PG A C D B ==> EE A B C D /\ EE A C B D /\ EA C A B B D C /\ EA A B D D C A /\ TC C A B B D C` Prop34.prf lemma diagonalsbisect `PG A B C D ==> ?X. MI A X C /\ MI B X D` diagonalsbisect.prf lemma trapezoiddiagonals `PG A B C D /\ BE A E D ==> ?X. BE B X D /\ BE C X E` trapezoiddiagonals.prf lemma ETreflexive `TR A B C ==> ET A B C A B C` ETreflexive.prf lemma PGflip `PG A B C D ==> PG B A D C` PGflip.prf lemma PGsymmetric `PG A B C D ==> PG C D A B` PGsymmetric.prf lemma PGrotate `PG A B C D ==> PG B C D A` PGrotate.prf proposition 33B `PR A B C D /\ EE A B C D /\ SS A C B D ==> PR A C B D /\ EE A C B D` Prop33B.prf lemma Playfairhelper `PR A B C D /\ PR A B C E /\ CR A D B C /\ CR A E B C ==> CO C D E` Playfairhelper.prf lemma Playfairhelper2 `PR A B C D /\ PR A B C E /\ CR A D B C ==> CO C D E` Playfairhelper2.prf lemma Playfair `PR A B C D /\ PR A B C E ==> CO C D E` Playfair.prf lemma triangletoparallelogram `PR D C E F /\ CO E F A ==> ?X. PG A X C D /\ CO E F X` triangletoparallelogram.prf lemma 35helper `PG A B C D /\ PG E B C F /\ BE A D F /\ CO A E F ==> BE A E F` 35helper.prf proposition 35A `PG A B C D /\ PG E B C F /\ BE A D F /\ CO A E F ==> EF A B C D E B C F` Prop35A.prf proposition 35 `PG A B C D /\ PG E B C F /\ CO A D E /\ CO A D F ==> EF A B C D E B C F` Prop35.prf proposition 36A `PG A B C D /\ PG E F G H /\ CO A D E /\ CO A D H /\ CO B C F /\ CO B C G /\ EE B C F G /\ BE B M H /\ BE C M E ==> EF A B C D E F G H` Prop36A.prf proposition 36 `PG A B C D /\ PG E F G H /\ CO A D E /\ CO A D H /\ CO B C F /\ CO B C G /\ EE B C F G ==> EF A B C D E F G H` Prop36.prf proposition 37 `PR A D B C ==> ET A B C D B C` Prop37.prf proposition 38 `PR P Q B C /\ CO P Q A /\ CO P Q D /\ EE B C E F /\ CO B C E /\ CO B C F ==> ET A B C D E F` Prop38.prf proposition 39A `TR A B C /\ ET A B C D B C /\ BE A M C /\ RA B D M ==> PR A D B C` Prop39A.prf proposition 39 `TR A B C /\ TR D B C /\ SS A D B C /\ ET A B C D B C /\ NE A D ==> PR A D B C` Prop39.prf proposition 40 `EE B C H E /\ ET A B C D H E /\ TR A B C /\ TR D H E /\ CO B C H /\ CO B C E /\ SS A D B C /\ NE A D ==> PR A D B C` Prop40.prf proposition 41 `PG A B C D /\ CO A D E ==> ET A B C E B C` Prop41.prf proposition 42 `TR A B C /\ NC J D K /\ MI B E C ==> ?X Z. PG X E C Z /\ EF A B E C X E C Z /\ EA C E X J D K /\ CO X Z A` Prop42.prf proposition 42B `TR a b c /\ MI b e c /\ NC J D K /\ MI B E C /\ EE E C e c /\ NC R E C ==> ?X Z. PG X E C Z /\ EF a b e c X E C Z /\ EA C E X J D K /\ SS R X E C` Prop42B.prf proposition 43 `PG A B C D /\ BE A H D /\ BE A E B /\ BE D F C /\ BE B G C /\ BE A K C /\ PG E A H K /\ PG G K F C ==> EF K G B E D F K H` Prop43.prf proposition 43B `PG A B C D /\ BE A H D /\ BE A E B /\ BE D F C /\ BE B G C /\ PG E A H K /\ PG G K F C ==> PG E K G B` Prop43B.prf proposition 44A `PG B E F G /\ EA E B G J D N /\ BE A B E ==> ?X Y. PG A B X Y /\ EA A B X J D N /\ EF B E F G Y X B A /\ BE G B X` Prop44A.prf proposition 44 `TR a b c /\ NC J D N /\ NC A B R ==> ?X Y Z. PG A B X Y /\ EA A B X J D N /\ EF a b Z c A B X Y /\ MI b Z c /\ OS X A B R` Prop44.prf proposition 45 `NC J E N /\ NC A B D /\ NC C B D /\ BE A O C /\ BE B O D /\ NE R K /\ NC K R S ==> ?X Z U. PG X K Z U /\ EA X K Z J E N /\ EF X K Z U A B C D /\ RA K R Z /\ SS X S K Z` Prop45.prf proposition 46 `NE A B /\ NC A B R ==> ?X Y. SQ A B X Y /\ OS Y A B R /\ PG A B X Y` Prop46.prf lemma righttogether `RR G A B /\ RR B A C /\ OS G B A C ==> RT G A B B A C /\ BE G A C` righttogether.prf lemma twoperpsparallel `RR A B C /\ RR B C D /\ SS A D B C ==> PR A B C D` twoperpsparallel.prf lemma squareparallelogram `SQ A B C D ==> PG A B C D` squareparallelogram.prf lemma squareunique `SQ A B C D /\ SQ A B C E ==> EQ E D` squareunique.prf lemma altitudeofrighttriangle `RR B A C /\ RR A M p /\ CO B C p /\ CO B C M ==> BE B M C` altitudeofrighttriangle.prf lemma squareflip `SQ A B C D ==> SQ B A D C` squareflip.prf proposition 47A `TR A B C /\ RR B A C /\ SQ B C E D /\ OS D C B A ==> ?X Y. PG B X Y D /\ BE B X C /\ PG X C E Y /\ BE D Y E /\ BE Y X A /\ RR D Y A` Prop47A.prf lemma angleaddition `AS A B C D E F P Q R /\ EA A B C a b c /\ EA D E F d e f /\ AS a b c d e f p q r ==> EA P Q R p q r` angleaddition.prf proposition 47B `TR A B C /\ RR B A C /\ SQ A B F G /\ OS G B A C /\ SQ B C E D /\ OS D C B A ==> ?X Y. PG B X Y D /\ BE B X C /\ PG X C E Y /\ BE D Y E /\ BE Y X A /\ RR D Y A /\ EF A B F G B X Y D` Prop47B.prf proposition 47 `TR A B C /\ RR B A C /\ SQ A B F G /\ OS G B A C /\ SQ A C K H /\ OS H C A B /\ SQ B C E D /\ OS D C B A ==> ?X Y. PG B X Y D /\ BE B X C /\ PG X C E Y /\ BE D Y E /\ EF A B F G B X Y D /\ EF A C K H X C E Y` Prop47.prf lemma rectangleparallelogram `RE A B C D ==> PG A B C D` rectangleparallelogram.prf lemma supplementofright `SU A B C D F /\ RR A B C ==> RR F B D /\ RR D B F` supplementofright.prf lemma PGrectangle `PG A C D B /\ RR B A C ==> RE A C D B` PGrectangle.prf lemma squarerectangle `SQ A B C D ==> RE A B C D` squarerectangle.prf lemma rectanglereverse `RE A B C D ==> RE D C B A` rectanglereverse.prf lemma rectanglerotate `RE A B C D ==> RE B C D A` rectanglerotate.prf lemma squaresequal `EE A B a b /\ SQ A B C D /\ SQ a b c d ==> EF A B C D a b c d` squaresequal.prf lemma paste5 `EF B M L D b m l d /\ EF M C E L m c e l /\ BE B M C /\ BE b m c /\ BE E L D /\ BE e l d /\ RE M C E L /\ RE m c e l ==> EF B C E D b c e d` paste5.prf proposition 48A `SQ A B C D /\ SQ a b c d /\ EF A B C D a b c d ==> EE A B a b` Prop48A.prf proposition 48 `TR A B C /\ SQ A B F G /\ SQ A C K H /\ SQ B C E D /\ BE B M C /\ BE E L D /\ EF A B F G B M L D /\ EF A C K H M C E L /\ RE M C E L ==> RR B A C` Prop48.prf lemma collinearmidpoint `CO A B M /\ NE A B /\ EE A M M B ==> BE A M B /\ MI A M B` collinearmidpoint.prf proposition III.01 `CI J G P Q /\ ON A J /\ ON B J /\ NE A B /\ MI A D B /\ ON C J /\ ON E J /\ PA C E A B D /\ SS C G A B /\ MI C F E /\ BE C D E ==> EQ G F` PropIII.01.prf lemma centerunique `CI J F P Q /\ CI J G p q ==> EQ F G` centerunique.prf lemma radiusdetermined `CI J F P Q /\ CI J G p q /\ NE P Q /\ NE p q ==> EE P Q p q` radiusdetermined.prf lemma radiiequal `CI J C P Q /\ ON A J /\ ON B J ==> EE C A C B` radiiequal.prf proposition III.02 `CI J D P Q /\ ON A J /\ ON B J /\ BE A E B ==> IC E J` PropIII.02.prf