Nuprl Lemma : left-convex2

∀g:EuclideanPlane. ∀a,b,x,y:Point.  (x leftof ab ⇒ (a_x_y ∨ (a_y_x ∧ y ≠ a)) ⇒ y leftof ab)


Proof




Definitions occuring in Statement :  euclidean-plane: EuclideanPlane,  geo-left: a leftof bc,  geo-between: a_b_c,  geo-sep: a ≠ b,  geo-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  and: P ∧ Q
Definitions unfolded in proof :  and: P ∧ Q,  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  all: ∀x:A. B[x],  or: P ∨ Q,  geo-lsep: a # bc,  subtract: n - m,  cons: [a / b],  select: L[n],  true: True,  squash: ↓T,  less_than: a < b,  not: ¬A,  false: False,  less_than': less_than'(a;b),  le: A ≤ B,  lelt: i ≤ j < k,  int_seg: {i..j-},  top: Top,  l_all: (∀x∈L.P[x]),  geo-colinear-set: geo-colinear-set(e; L),  cand: A c∧ B
Lemmas referenced :  geo-point_wf,  geo-left_wf,  geo-sep_wf,  geo-primitives_wf,  euclidean-plane-structure_wf,  euclidean-plane_wf,  subtype_rel_transitivity,  euclidean-plane-subtype,  euclidean-plane-structure-subtype,  geo-between_wf,  or_wf,  left-symmetry,  lelt_wf,  false_wf,  length_of_nil_lemma,  length_of_cons_lemma,  geo-between-implies-colinear,  geo-colinear-is-colinear-set,  left-implies-sep,  geo-between-sep,  geo-sep-sym,  colinear-lsep,  lsep-symmetry,  not-left-and-right,  left-convex
Rules used in proof :  because_Cache,  productEquality,  sqequalRule,  independent_isectElimination,  instantiate,  hypothesis,  applyEquality,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  independent_functionElimination,  dependent_functionElimination,  inlFormation,  unionElimination,  baseClosed,  imageMemberEquality,  independent_pairFormation,  natural_numberEquality,  dependent_set_memberEquality,  voidEquality,  voidElimination,  isect_memberEquality,  productElimination,  inrFormation

Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,x,y:Point.    (x  leftof  ab  {}\mRightarrow{}  (a\_x\_y  \mvee{}  (a\_y\_x  \mwedge{}  y  \mneq{}  a))  {}\mRightarrow{}  y  leftof  ab)



Date html generated: 2017_10_02-PM-04_40_41
Last ObjectModification: 2017_08_08-PM-03_52_22

Theory : euclidean!plane!geometry


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