Nuprl Lemma : not-col-distincts

∀e:BasicGeometry. ∀A,B,C:Point.  ((¬Colinear(A;B;C)) ⇒ (¬¬(A ≠ B ∧ B ≠ C ∧ A ≠ C)))


Proof




Definitions occuring in Statement :  basic-geometry: BasicGeometry,  geo-colinear: Colinear(a;b;c),  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q
Definitions unfolded in proof :  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  geo-eq: a ≡ b,  or: P ∨ Q,  stable: Stable{P},  cand: A c∧ B,  basic-geometry: BasicGeometry,  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  and: P ∧ Q,  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  false: False,  not: ¬A,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  minimal-not-not-excluded-middle,  geo-colinear_functionality,  geo-eq_weakening,  geo-sep_functionality,  minimal-double-negation-hyp-elim,  geo-colinear-same,  or_wf,  false_wf,  stable__false,  geo-point_wf,  geo-colinear_wf,  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf,  subtype_rel_transitivity,  basic-geometry-subtype,  geo-sep_wf,  not_wf
Rules used in proof :  impliesLevelFunctionality,  promote_hyp,  levelHypothesis,  andLevelFunctionality,  dependent_functionElimination,  impliesFunctionality,  addLevel,  unionElimination,  productElimination,  independent_pairFormation,  functionEquality,  rename,  setElimination,  sqequalRule,  independent_isectElimination,  instantiate,  applyEquality,  hypothesisEquality,  productEquality,  isectElimination,  extract_by_obid,  introduction,  voidElimination,  independent_functionElimination,  sqequalHypSubstitution,  hypothesis,  because_Cache,  thin,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}e:BasicGeometry.  \mforall{}A,B,C:Point.    ((\mneg{}Colinear(A;B;C))  {}\mRightarrow{}  (\mneg{}\mneg{}(A  \mneq{}  B  \mwedge{}  B  \mneq{}  C  \mwedge{}  A  \mneq{}  C)))



Date html generated: 2017_10_02-PM-06_32_12
Last ObjectModification: 2017_08_05-PM-04_43_01

Theory : euclidean!plane!geometry


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