Nuprl Lemma : geo-congruent-mid-exists

∀e:HeytingGeometry. ∀A,B,C:Point.  (A # BC ⇒ CA ≅ CB ⇒ (∃x:Point. A=x=B))


Proof




Definitions occuring in Statement :  geo-triangle: a # bc,  heyting-geometry: HeytingGeometry,  geo-midpoint: a=m=b,  geo-congruent: ab ≅ cd,  geo-point: Point,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  heyting-geometry: Error :heyting-geometry,  prop: ℙ,  uimplies: b supposing a,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  cand: A c∧ B,  and: P ∧ Q,  guard: {T},  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  geo-point_wf,  Error :geo-triangle_wf,  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf,  Error :heyting-geometry_wf,  subtype_rel_transitivity,  basic-geometry-subtype,  geo-congruent_wf,  geo-length-flip,  heyting-geometry-subtype,  geo-congruent-iff-length,  geo-triangle-symmetry,  isosceles-mid-exists
Rules used in proof :  rename,  setElimination,  instantiate,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  isectElimination,  sqequalRule,  applyEquality,  productElimination,  hypothesis,  because_Cache,  independent_functionElimination,  hypothesisEquality,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}e:HeytingGeometry.  \mforall{}A,B,C:Point.    (A  \#  BC  {}\mRightarrow{}  CA  \00D0  CB  {}\mRightarrow{}  (\mexists{}x:Point.  A=x=B))



Date html generated: 2017_10_02-PM-07_09_30
Last ObjectModification: 2017_08_08-PM-00_41_08

Theory : euclidean!plane!geometry


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