Nuprl Lemma : geo-lt-angle-degenerate-case1

∀e:EuclideanPlane. ∀a,b,x,y,z:Point.  (a ≠ b ⇒ x-y-z ⇒ aba < xyz)


Proof




Definitions occuring in Statement :  geo-lt-angle: abc < xyz,  euclidean-plane: EuclideanPlane,  geo-strict-between: a-b-c,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  geo-lt-angle: abc < xyz,  and: P ∧ Q,  member: t ∈ T,  basic-geometry: BasicGeometry,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  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,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  basic-geometry-: BasicGeometry-,  subtype_rel: A ⊆r B,  guard: {T},  cand: A c∧ B
Lemmas referenced :  geo-colinear-not-out,  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-strict-between-implies-between,  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-sep_wf,  geo-point_wf,  geo-between-trivial2,  geo-out_weakening,  geo-sep-sym,  geo-strict-between-sep2,  geo-eq_weakening,  geo-strict-between-sep3,  geo-out-iff-colinear,  geo-between-symmetry,  geo-between-inner-trans,  geo-between-exchange3,  euclidean-plane-axioms,  geo-cong-angle_wf,  geo-between_wf,  geo-out_wf,  geo-between-trivial,  zero-angles-congruent
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  independent_pairFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  sqequalRule,  hypothesisEquality,  independent_functionElimination,  because_Cache,  isectElimination,  independent_isectElimination,  hypothesis,  isect_memberEquality_alt,  voidElimination,  dependent_set_memberEquality_alt,  natural_numberEquality,  unionElimination,  approximateComputation,  dependent_pairFormation_alt,  lambdaEquality_alt,  universeIsType,  productIsType,  productElimination,  applyEquality,  instantiate,  inhabitedIsType,  functionIsType

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,x,y,z:Point.    (a  \mneq{}  b  {}\mRightarrow{}  x-y-z  {}\mRightarrow{}  aba  <  xyz)



Date html generated: 2019_10_16-PM-01_57_17
Last ObjectModification: 2019_09_27-PM-04_57_42

Theory : euclidean!plane!geometry


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