Nuprl Lemma : lsep-opposite-iff

∀g:OrientedPlane. ∀a,b,x,y:Point.
  (x # ab ⇒ y # ab ⇒ (∃z:Point. (x_z_y ∧ Colinear(z;a;b)) ⇐⇒ x leftof ab ⇐⇒ y leftof ba))


Proof




Definitions occuring in Statement :  oriented-plane: OrientedPlane,  geo-lsep: a # bc,  geo-colinear: Colinear(a;b;c),  geo-left: a leftof bc,  geo-between: a_b_c,  geo-point: Point,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  and: P ∧ Q
Definitions unfolded in proof :  so_apply: x[s],  so_lambda: λ2x.t[x],  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  false: False,  not: ¬A,  rev_implies: P ⇐ Q,  oriented-plane: Error :oriented-plane,  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  or: P ∨ Q,  geo-lsep: a # bc,  exists: ∃x:A. B[x],  and: P ∧ Q,  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  all: ∀x:A. B[x],  cand: A c∧ B,  euclidean-geometry: Error :euclidean-geometry
Lemmas referenced :  geo-lsep_wf,  iff_wf,  geo-colinear_wf,  geo-between_wf,  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry-_wf,  Error :oriented-plane_wf,  subtype_rel_transitivity,  Error :oriented-plane-subtype,  basic-geometry--subtype,  geo-point_wf,  exists_wf,  not-left-and-right,  geo-left_wf,  left-between-weak,  Error :use-plane-sep,  lsep-symmetry,  lsep-symmetry2,  Error :euclidean-geometry_wf,  subtype_rel_self
Rules used in proof :  productEquality,  lambdaEquality,  sqequalRule,  independent_isectElimination,  instantiate,  applyEquality,  voidElimination,  independent_functionElimination,  dependent_functionElimination,  hypothesisEquality,  hypothesis,  because_Cache,  rename,  setElimination,  isectElimination,  extract_by_obid,  introduction,  cut,  unionElimination,  thin,  productElimination,  sqequalHypSubstitution,  independent_pairFormation,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  inlFormation,  inrFormation,  dependent_pairFormation

Latex:
\mforall{}g:OrientedPlane.  \mforall{}a,b,x,y:Point.
    (x  \#  ab  {}\mRightarrow{}  y  \#  ab  {}\mRightarrow{}  (\mexists{}z:Point.  (x\_z\_y  \mwedge{}  Colinear(z;a;b))  \mLeftarrow{}{}\mRightarrow{}  x  leftof  ab  \mLeftarrow{}{}\mRightarrow{}  y  leftof  ba))



Date html generated: 2017_10_02-PM-04_47_39
Last ObjectModification: 2017_08_05-AM-10_20_20

Theory : euclidean!plane!geometry


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