Nuprl Lemma : common-P_point-intersecting-P_lines

∀e:EuclideanParPlane. ∀P:P_point(e). ∀L:P_line(e).
  ((¬P_point-line-sep(e;P;L))
  ⇒ (fst(snd(P)) \/ fst(snd(snd(P))) ∧ (∀l,m,n:Line.  (l \/ m ⇒ (l \/ n ∨ m \/ n))))
  ⇒ (∃x:Point. ((x I fst(snd(P)) ∧ x I fst(snd(snd(P)))) ∧ x I fst(L))))


Proof




Definitions occuring in Statement :  P_point-line-sep: P_point-line-sep(e;P;L),  P_line: P_line(eu),  P_point: P_point(eu),  euclidean-parallel-plane: EuclideanParPlane,  geo-intersect: L \/ M,  geo-incident: p I L,  geo-line: Line,  geo-point: Point,  pi1: fst(t),  pi2: snd(t),  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  or: P ∨ Q,  and: P ∧ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  P_point: P_point(eu),  P_line: P_line(eu),  pi2: snd(t),  pi1: fst(t),  member: t ∈ T,  euclidean-parallel-plane: EuclideanParPlane,  iff: P ⇐⇒ Q,  exists: ∃x:A. B[x],  prop: ℙ,  uall: ∀[x:A]. B[x],  P_point-line-sep: P_point-line-sep(e;P;L),  subtype_rel: A ⊆r B,  guard: {T},  uimplies: b supposing a,  so_lambda: λ2x.t[x],  or: P ∨ Q,  so_apply: x[s],  cand: A c∧ B,  not: ¬A,  false: False,  sq_stable: SqStable(P),  squash: ↓T,  rev_implies: P ⇐ Q,  geo-plsep: p # l,  geo-line: Line,  top: Top,  geo-line-sep: (l # m),  uiff: uiff(P;Q)
Lemmas referenced :  geo-intersect-lines-iff,  geo-intersect_wf,  geoline-subtype1,  all_wf,  geo-line_wf,  euclidean-plane-structure-subtype,  euclidean-plane-subtype,  euclidean-planes-subtype,  subtype_rel_transitivity,  euclidean-parallel-plane_wf,  euclidean-plane_wf,  euclidean-plane-structure_wf,  geo-primitives_wf,  or_wf,  not_wf,  P_point-line-sep_wf,  P_line_wf,  P_point_wf,  geo-incident_wf,  geo-plsep_wf,  geo-intersect-unique,  sq_stable__incident,  set_wf,  geo-point_wf,  geo-plsep_functionality,  geo-line-eq_weakening2,  not-lsep-iff-colinear,  pi1_wf_top,  geo-incident-line
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  sqequalRule,  cut,  introduction,  extract_by_obid,  dependent_functionElimination,  setElimination,  rename,  hypothesisEquality,  hypothesis,  independent_functionElimination,  productEquality,  isectElimination,  because_Cache,  applyEquality,  instantiate,  independent_isectElimination,  lambdaEquality,  functionEquality,  unionElimination,  dependent_pairFormation,  independent_pairFormation,  voidElimination,  inlFormation,  imageMemberEquality,  baseClosed,  imageElimination,  independent_pairEquality,  isect_memberEquality,  voidEquality,  inrFormation

Latex:
\mforall{}e:EuclideanParPlane.  \mforall{}P:P\_point(e).  \mforall{}L:P\_line(e).
    ((\mneg{}P\_point-line-sep(e;P;L))
    {}\mRightarrow{}  (fst(snd(P))  \mbackslash{}/  fst(snd(snd(P)))  \mwedge{}  (\mforall{}l,m,n:Line.    (l  \mbackslash{}/  m  {}\mRightarrow{}  (l  \mbackslash{}/  n  \mvee{}  m  \mbackslash{}/  n))))
    {}\mRightarrow{}  (\mexists{}x:Point.  ((x  I  fst(snd(P))  \mwedge{}  x  I  fst(snd(snd(P))))  \mwedge{}  x  I  fst(L))))



Date html generated: 2019_10_16-PM-03_03_10
Last ObjectModification: 2018_08_11-PM-10_21_04

Theory : euclidean!plane!geometry


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