Nuprl Lemma : geo-gt-implies-point

∀e:EuclideanPlane. ∀a,b,c,d:Point.  (ab > cd ⇒ c ≠ d ⇒ (¬¬(∃f:Point. (c-d-f ∧ cf ≅ ab))))


Proof




Definitions occuring in Statement :  euclidean-plane: EuclideanPlane,  geo-strict-between: a-b-c,  geo-gt: cd > ab,  geo-congruent: ab ≅ cd,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  not: ¬A,  false: False,  geo-gt: cd > ab,  squash: ↓T,  exists: ∃x:A. B[x],  and: P ∧ Q,  member: t ∈ T,  basic-geometry: BasicGeometry,  euclidean-plane: EuclideanPlane,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  guard: {T},  uimplies: b supposing a,  basic-geometry-: BasicGeometry-,  uiff: uiff(P;Q),  cand: A c∧ B,  prop: ℙ,  true: True
Lemmas referenced :  geo-proper-extend-exists,  geo-O_wf,  geo-X_wf,  geo-sep-sym,  geo-sep-O-X,  geo-strict-between-sep3,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-congruent-sep,  geo-construction-unicity,  geo-between-symmetry,  geo-strict-between-implies-between,  geo-congruent-iff-length,  geo-eq_inversion,  geo-add-length-between,  geo-add-length_wf,  squash_wf,  true_wf,  geo-length-type_wf,  basic-geometry_wf,  geo-strict-between_wf,  geo-congruent_wf,  istype-void,  geo-sep_wf,  geo-gt_wf,  geo-point_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  thin,  sqequalHypSubstitution,  imageElimination,  productElimination,  introduction,  extract_by_obid,  dependent_functionElimination,  sqequalRule,  hypothesisEquality,  setElimination,  rename,  hypothesis,  because_Cache,  independent_functionElimination,  applyEquality,  instantiate,  isectElimination,  independent_isectElimination,  equalityTransitivity,  dependent_pairFormation_alt,  independent_pairFormation,  lambdaEquality_alt,  equalitySymmetry,  universeIsType,  inhabitedIsType,  natural_numberEquality,  imageMemberEquality,  baseClosed,  productIsType,  voidElimination,  functionIsType

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d:Point.    (ab  >  cd  {}\mRightarrow{}  c  \mneq{}  d  {}\mRightarrow{}  (\mneg{}\mneg{}(\mexists{}f:Point.  (c-d-f  \mwedge{}  cf  \mcong{}  ab))))



Date html generated: 2019_10_16-PM-01_17_14
Last ObjectModification: 2019_08_07-PM-02_43_56

Theory : euclidean!plane!geometry


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