Nuprl Lemma : left-between-implies-right1

∀g:OrientedPlane. ∀a,b,x,y:Point.  (x leftof ab ⇒ x_b_y ⇒ y ≠ b ⇒ y leftof ba)


Proof




Definitions occuring in Statement :  oriented-plane: OrientedPlane,  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
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  oriented-plane: OrientedPlane,  guard: {T},  and: P ∧ Q,  cand: A c∧ B,  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,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  prop: ℙ,  less_than: a < b,  squash: ↓T,  true: True,  select: L[n],  cons: [a / b],  subtract: n - m,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  exists: ∃x:A. B[x]
Lemmas referenced :  lsep-opposite-iff,  lsep-all-sym2,  colinear-lsep-cycle,  geo-colinear-is-colinear-set,  geo-between-implies-colinear,  length_of_cons_lemma,  length_of_nil_lemma,  false_wf,  lelt_wf,  lsep-all-sym,  geo-sep_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  oriented-plane-subtype,  subtype_rel_transitivity,  oriented-plane_wf,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  geo-between_wf,  geo-left_wf,  geo-point_wf,  geo-colinear-same,  euclidean-plane-subtype-basic,  basic-geometry_wf,  geo-colinear_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  because_Cache,  hypothesis,  productElimination,  isectElimination,  independent_isectElimination,  sqequalRule,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_set_memberEquality,  natural_numberEquality,  independent_pairFormation,  imageMemberEquality,  baseClosed,  applyEquality,  instantiate,  dependent_pairFormation,  productEquality

Latex:
\mforall{}g:OrientedPlane.  \mforall{}a,b,x,y:Point.    (x  leftof  ab  {}\mRightarrow{}  x\_b\_y  {}\mRightarrow{}  y  \mneq{}  b  {}\mRightarrow{}  y  leftof  ba)



Date html generated: 2018_05_22-AM-11_54_44
Last ObjectModification: 2018_04_17-PM-05_54_20

Theory : euclidean!plane!geometry


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