Nuprl Lemma : geo-between-middle-or

∀e:BasicGeometry. ∀a,b,c,d:Point.  (a ≠ b ⇒ b ≠ c ⇒ b ≠ d ⇒ a_b_d ⇒ a_c_d ⇒ (b_c_d ∨ c_b_d))


Proof




Definitions occuring in Statement :  basic-geometry: BasicGeometry,  geo-between: a_b_c,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  guard: {T},  uimplies: b supposing a,  prop: ℙ,  and: P ∧ Q,  not: ¬A,  false: False,  or: P ∨ Q,  iff: P ⇐⇒ Q,  basic-geometry: BasicGeometry,  euclidean-plane: EuclideanPlane,  basic-geometry-: BasicGeometry-,  exists: ∃x:A. B[x],  stable: Stable{P},  geo-eq: a ≡ b,  cand: A c∧ B
Lemmas referenced :  geo-between_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  basic-geometry-subtype,  subtype_rel_transitivity,  basic-geometry_wf,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-sep_wf,  geo-point_wf,  geo-sep-sym,  geo-strict-between-sep3,  iff_weakening_uiff,  not_wf,  not_over_or,  istype-void,  geo-between-middle,  geo-between-sep,  geo-sep-or,  geo-strict-between-sep1,  subtype_rel_self,  basic-geometry-_wf,  geo-proper-extend-exists,  stable__geo-between,  double-negation-hyp-elim,  geo-construction-unicity,  geo-between-symmetry,  geo-strict-between-implies-between,  geo-between-inner-trans,  extended-out-preserves-between,  geo-out-iff-between1,  euclidean-plane-axioms
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  universeIsType,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  applyEquality,  hypothesis,  instantiate,  independent_isectElimination,  sqequalRule,  because_Cache,  inhabitedIsType,  productElimination,  dependent_functionElimination,  independent_functionElimination,  unionEquality,  productEquality,  voidElimination,  functionIsType,  unionIsType,  productIsType,  setElimination,  rename,  dependent_set_memberEquality_alt,  unionElimination,  inrFormation_alt,  inlFormation_alt,  independent_pairFormation

Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c,d:Point.    (a  \mneq{}  b  {}\mRightarrow{}  b  \mneq{}  c  {}\mRightarrow{}  b  \mneq{}  d  {}\mRightarrow{}  a\_b\_d  {}\mRightarrow{}  a\_c\_d  {}\mRightarrow{}  (b\_c\_d  \mvee{}  c\_b\_d))



Date html generated: 2019_10_16-PM-01_24_49
Last ObjectModification: 2019_01_13-PM-00_56_38

Theory : euclidean!plane!geometry


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