Nuprl Lemma : geo-gt-implies-point

e:EuclideanPlane. ∀a,b,c,d:Point.  (ab > cd  c ≠  (¬¬(∃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:  Q and: P ∧ Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  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 ⊆B uall: [x:A]. B[x] guard: {T} uimplies: supposing a basic-geometry-: BasicGeometry- uiff: uiff(P;Q) cand: c∧ B prop: 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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