Nuprl Lemma : eu-eq_dist-axiomA9

∀e:EuclideanPlane. ∀a1,a2,a3,a4,a5,a6,b:Point.  (D(a1;a2;a3;a4;a5;a6) ⇒ (a4 ≠ b ∨ D(a1;a2;a3;b;a5;a6)))


Proof




Definitions occuring in Statement :  dist: D(a;b;c;d;e;f),  euclidean-plane: EuclideanPlane,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  prop: ℙ,  or: P ∨ Q,  rev_implies: P ⇐ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  euclidean-plane: EuclideanPlane,  uall: ∀[x:A]. B[x],  basic-geometry: BasicGeometry,  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  geo-point_wf,  dist_wf,  geo-primitives_wf,  euclidean-plane-structure_wf,  euclidean-plane_wf,  subtype_rel_transitivity,  euclidean-plane-subtype,  euclidean-plane-structure-subtype,  geo-sep_wf,  geo-sep-or,  geo-length_wf,  geo-add-length_wf,  geo-lt_wf,  geo-add-length_wf1,  geo-mk-seg_wf,  geo-length_wf1,  geo-sep-iff-or-lt,  dist-lemma-lt,  dist-lemma-lt2,  geo-add-length-cancel-left-lt,  geo-le_weakening-lt,  geo-lt_transitivity,  geo-lt-lengths-to-sep,  geo-sep-sym
Rules used in proof :  unionElimination,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  instantiate,  dependent_set_memberEquality_alt,  inhabitedIsType,  lambdaEquality_alt,  applyEquality,  universeIsType,  inlFormation_alt,  productElimination,  because_Cache,  rename,  setElimination,  isectElimination,  sqequalRule,  hypothesis,  independent_functionElimination,  hypothesisEquality,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation_alt,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  inrFormation_alt

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a1,a2,a3,a4,a5,a6,b:Point.
    (D(a1;a2;a3;a4;a5;a6)  {}\mRightarrow{}  (a4  \mneq{}  b  \mvee{}  D(a1;a2;a3;b;a5;a6)))



Date html generated: 2019_10_16-PM-02_57_56
Last ObjectModification: 2019_04_22-PM-01_32_18

Theory : euclidean!plane!geometry


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