Nuprl Lemma : Euclid-prop14

∀g:EuclideanPlane. ∀a,b,x,y:Point.  (a ≠ b ⇒ x leftof ab ⇒ y leftof ba ⇒ Rxba ⇒ Ryba ⇒ Colinear(x;b;y))


Proof




Definitions occuring in Statement :  euclidean-plane: EuclideanPlane,  right-angle: Rabc,  geo-colinear: Colinear(a;b;c),  geo-left: a leftof bc,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  basic-geometry: BasicGeometry,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  guard: {T},  uimplies: b supposing a,  prop: ℙ
Lemmas referenced :  adjacent-right-angles,  geo-sep-sym,  right-angle_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-left_wf,  geo-sep_wf,  geo-point_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  sqequalRule,  hypothesisEquality,  independent_functionElimination,  because_Cache,  hypothesis,  universeIsType,  isectElimination,  applyEquality,  instantiate,  independent_isectElimination,  inhabitedIsType

Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,x,y:Point.
    (a  \mneq{}  b  {}\mRightarrow{}  x  leftof  ab  {}\mRightarrow{}  y  leftof  ba  {}\mRightarrow{}  Rxba  {}\mRightarrow{}  Ryba  {}\mRightarrow{}  Colinear(x;b;y))



Date html generated: 2019_10_16-PM-01_55_51
Last ObjectModification: 2018_10_15-PM-00_32_06

Theory : euclidean!plane!geometry


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