Nuprl Lemma : not-lt-zero-angle

∀e:EuclideanPlane. ∀a,b,c,x,y,z:Point.  (abc < xyz ⇒ (y_z_x ∨ y_x_z) ⇒ False)


Proof




Definitions occuring in Statement :  geo-lt-angle: abc < xyz,  euclidean-plane: EuclideanPlane,  geo-between: a_b_c,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  false: False
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  false: False,  geo-lt-angle: abc < xyz,  and: P ∧ Q,  exists: ∃x:A. B[x],  or: P ∨ Q,  member: t ∈ T,  basic-geometry: BasicGeometry,  geo-out: out(p ab),  not: ¬A,  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  guard: {T},  uimplies: b supposing a,  prop: ℙ
Lemmas referenced :  geo-out_inversion,  geo-between-out,  euclidean-plane-axioms,  geo-sep-sym,  geo-between_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  subtype_rel_transitivity,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-lt-angle_wf,  geo-point_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  sqequalHypSubstitution,  productElimination,  thin,  unionElimination,  introduction,  extract_by_obid,  dependent_functionElimination,  sqequalRule,  hypothesisEquality,  independent_functionElimination,  because_Cache,  hypothesis,  voidElimination,  unionIsType,  universeIsType,  isectElimination,  applyEquality,  instantiate,  independent_isectElimination,  inhabitedIsType

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x,y,z:Point.    (abc  <  xyz  {}\mRightarrow{}  (y\_z\_x  \mvee{}  y\_x\_z)  {}\mRightarrow{}  False)



Date html generated: 2019_10_16-PM-01_49_25
Last ObjectModification: 2019_09_27-PM-05_58_24

Theory : euclidean!plane!geometry


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