Nuprl Lemma : Euclid-Prop19-lemma1

∀e:EuclideanPlane. ∀a,b,c,d:Point.  (a # bc ⇒ bad ≅a cad ⇒ b-d-c ⇒ |bd| < |cd| ⇒ |ab| < |ac|)


Proof




Definitions occuring in Statement :  geo-cong-angle: abc ≅a xyz,  geo-lt: p < q,  geo-length: |s|,  geo-mk-seg: ab,  euclidean-plane: EuclideanPlane,  geo-lsep: a # bc,  geo-strict-between: a-b-c,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  guard: {T},  and: P ∧ Q,  cand: A c∧ B,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  basic-geometry: BasicGeometry,  geo-colinear-set: geo-colinear-set(e; L),  l_all: (∀x∈L.P[x]),  top: Top,  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  prop: ℙ,  false: False,  select: L[n],  cons: [a / b],  subtract: n - m,  euclidean-plane: EuclideanPlane,  uiff: uiff(P;Q),  squash: ↓T,  true: True,  iff: P ⇐⇒ Q,  basic-geometry-: BasicGeometry-,  rev_implies: P ⇐ Q,  sq_exists: ∃x:A [B[x]],  sq_stable: SqStable(P),  geo-midpoint: a=m=b,  heyting-geometry: HeytingGeometry,  geo-triangle: a # bc,  geo-tri: Triangle(a;b;c),  geo-lt: p < q,  geo-strict-between: a-b-c
Lemmas referenced :  colinear-lsep,  lsep-all-sym,  geo-sep-sym,  geo-strict-between-sep2,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-colinear-is-colinear-set,  geo-strict-between-implies-colinear,  length_of_cons_lemma,  istype-void,  length_of_nil_lemma,  decidable__le,  full-omega-unsat,  intformnot_wf,  intformle_wf,  itermConstant_wf,  istype-int,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  istype-le,  istype-less_than,  geo-lt_wf,  geo-length_wf,  geo-mk-seg_wf,  geo-strict-between_wf,  geo-cong-angle_wf,  geo-lsep_wf,  geo-point_wf,  lsep-implies-sep,  geo-congruent-iff-length,  squash_wf,  true_wf,  geo-length-type_wf,  basic-geometry_wf,  subtype_rel_self,  iff_weakening_equal,  geo-lt-out-to-between,  geo-out-iff-between1,  euclidean-plane-axioms,  geo-strict-between-sep3,  geo-between-symmetry,  geo-strict-between-implies-between,  geo-length-flip,  geo-congruent_wf,  geo-proper-extend-exists,  lsep-symmetry,  colinear-lsep-cycle,  geo-strict-between-sep1,  outer-pasch-strict,  geo-between-outer-trans,  geo-between_wf,  sq_stable__and,  sq_stable__geo-strict-between,  geo-midpoint-diagonals-congruent,  vert-angles-congruent,  Euclid-Prop4,  geo-between-out,  geo-out_weakening,  geo-eq_weakening,  geo-out_inversion,  geo-cong-angle-symm2,  out-cong-angle,  geo-cong-angle-transitivity,  out-preserves-lsep,  Euclid-Prop6,  out-preserves-angle-cong_1,  geo-add-length-between,  geo-le_weakening,  geo-sep_wf,  geo-le_wf,  geo-add-length_wf,  geo-lt_transitivity,  geo-le_weakening-lt
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  because_Cache,  hypothesis,  productElimination,  applyEquality,  instantiate,  isectElimination,  independent_isectElimination,  sqequalRule,  isect_memberEquality_alt,  voidElimination,  dependent_set_memberEquality_alt,  natural_numberEquality,  independent_pairFormation,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  universeIsType,  productIsType,  setElimination,  rename,  inhabitedIsType,  equalitySymmetry,  imageElimination,  equalityTransitivity,  imageMemberEquality,  baseClosed,  universeEquality

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d:Point.    (a  \#  bc  {}\mRightarrow{}  bad  \mcong{}\msuba{}  cad  {}\mRightarrow{}  b-d-c  {}\mRightarrow{}  |bd|  <  |cd|  {}\mRightarrow{}  |ab|  <  |ac|)



Date html generated: 2019_10_16-PM-02_16_11
Last ObjectModification: 2018_12_14-PM-00_54_26

Theory : euclidean!plane!geometry


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