Nuprl Lemma : geo-le-pt-switch-congruence

∀e:BasicGeometry. ∀a,b,c,d:Point.  (a ≠ b ⇒ ab≤cd ⇒ cd≤ab ⇒ ab ≅ cd)


Proof




Definitions occuring in Statement :  geo-le-pt: ab≤cd,  basic-geometry: BasicGeometry,  geo-congruent: ab ≅ cd,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  basic-geometry: BasicGeometry,  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x],  and: P ∧ Q,  exists: ∃x:A. B[x],  geo-le-pt: ab≤cd,  uiff: uiff(P;Q),  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  true: True,  squash: ↓T
Lemmas referenced :  geo-point_wf,  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf,  subtype_rel_transitivity,  basic-geometry-subtype,  geo-sep_wf,  geo-le-pt_wf,  geo-le-pt-exists,  geo-congruent-sep,  geo-congruent-symmetry,  geo-between-sep,  geo-add-length-between,  geo-eq_inversion,  geo-congruent-iff-length,  geo-between-exchange4,  geo-between-exchange3,  geo-between-inner-trans,  geo-between-symmetry,  geo-between-congruent,  geo-length_functionality,  geo-eq_weakening,  iff_weakening_equal,  geo-length-flip,  true_wf,  squash_wf,  geo-mk-seg_wf,  geo-length_wf,  geo-length-type_wf,  equal_wf,  geo-add-length_wf,  geo-add-length-assoc,  geo-add-length-implies-eq2,  geo-add-length-zero2
Rules used in proof :  because_Cache,  sqequalRule,  independent_isectElimination,  instantiate,  applyEquality,  hypothesis,  hypothesisEquality,  rename,  setElimination,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  independent_functionElimination,  dependent_functionElimination,  productElimination,  equalitySymmetry,  equalityTransitivity,  universeEquality,  applyLambdaEquality,  hyp_replacement,  baseClosed,  imageMemberEquality,  natural_numberEquality,  imageElimination,  lambdaEquality

Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c,d:Point.    (a  \mneq{}  b  {}\mRightarrow{}  ab\mleq{}cd  {}\mRightarrow{}  cd\mleq{}ab  {}\mRightarrow{}  ab  \00D0  cd)



Date html generated: 2017_10_02-PM-06_46_37
Last ObjectModification: 2017_08_05-PM-04_51_28

Theory : euclidean!plane!geometry


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