Nuprl Lemma : Euclid-Prop19-lemma2

∀e:EuclideanPlane. ∀a,b,c,d,f:Point.  (a # bc ⇒ cbd < abd ⇒ a=d=c ⇒ a-f-c ⇒ cbf ≅a abf ⇒ |af| < |cf|)


Proof




Definitions occuring in Statement :  geo-lt-angle: abc < xyz,  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-midpoint: a=m=b,  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,  basic-geometry-: BasicGeometry-,  guard: {T},  and: P ∧ Q,  cand: A c∧ B,  uall: ∀[x:A]. B[x],  basic-geometry: BasicGeometry,  prop: ℙ,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  exists: ∃x:A. B[x],  geo-out: out(p ab),  geo-midpoint: a=m=b,  uiff: uiff(P;Q),  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),  false: False,  select: L[n],  cons: [a / b],  subtract: n - m,  geo-strict-between: a-b-c,  geo-lt: p < q,  squash: ↓T,  true: True,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  euclidean-plane: EuclideanPlane
Lemmas referenced :  geo-equilateral-exists,  lsep-all-sym,  geo-cong-angle_wf,  geo-strict-between_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-midpoint_wf,  geo-lt-angle_wf,  geo-lsep_wf,  geo-point_wf,  geo-out_weakening,  lsep-implies-sep,  geo-eq_weakening,  geo-midpoint-implies-between,  geo-out-interior-point-exists,  Euclid-Prop19-lemma2_1,  euclidean-plane-axioms,  geo-sep-sym,  geo-cong-angle-symm2,  geo-cong-angle-transitivity,  geo-congruent-refl,  geo-strict-between-implies-between,  geo-congruent-iff-length,  geo-length-flip,  geo-sas2,  lsep-symmetry,  colinear-lsep-cycle,  geo-strict-between-sep2,  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-cong-angle-preserves-lt-angle,  geo-cong-angle-preserves-lt-angle2,  midpoint-sep,  geo-between-implies-colinear,  lt-angle-implies-between-if-out,  geo-between-implies-out3,  geo-between-symmetry,  geo-between-exchange3,  geo-congruent-symmetry,  geo-congruent-sep,  geo-strict-between-sep1,  geo-strict-between-sep3,  geo-add-length-between,  geo-le_wf,  iff_weakening_equal,  geo-le-same,  geo-sep_wf,  geo-add-length_wf,  geo-length_wf,  geo-mk-seg_wf,  geo-lt_wf,  geo-lt_transitivity2,  geo-le_weakening-lt
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  sqequalRule,  hypothesisEquality,  independent_functionElimination,  because_Cache,  hypothesis,  productElimination,  universeIsType,  isectElimination,  applyEquality,  instantiate,  independent_isectElimination,  inhabitedIsType,  independent_pairFormation,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality_alt,  voidElimination,  dependent_set_memberEquality_alt,  natural_numberEquality,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  productIsType,  imageElimination,  imageMemberEquality,  baseClosed,  setElimination,  rename

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d,f:Point.
    (a  \#  bc  {}\mRightarrow{}  cbd  <  abd  {}\mRightarrow{}  a=d=c  {}\mRightarrow{}  a-f-c  {}\mRightarrow{}  cbf  \mcong{}\msuba{}  abf  {}\mRightarrow{}  |af|  <  |cf|)



Date html generated: 2019_10_16-PM-02_18_35
Last ObjectModification: 2019_09_12-AM-11_42_01

Theory : euclidean!plane!geometry


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