Nuprl Lemma : Euclid-erect-perp-on-same-side

e:EuclideanPlane. ∀a:Point. ∀b:{b:Point| a ≠ b} . ∀c:{c:Point| Colinear(a;b;c)} . ∀q:{q:Point| ab} .
  (∃p:Point [(ab  ⊥pc ∧ ab ∧ (p leftof ab ⇐⇒ leftof ab))])


Proof




Definitions occuring in Statement :  geo-perp-in: ab  ⊥cd euclidean-plane: EuclideanPlane geo-lsep: bc geo-colinear: Colinear(a;b;c) geo-left: leftof bc geo-sep: a ≠ b geo-point: Point all: x:A. B[x] sq_exists: x:A [B[x]] iff: ⇐⇒ Q and: P ∧ Q set: {x:A| B[x]} 
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T euclidean-plane: EuclideanPlane sq_stable: SqStable(P) implies:  Q squash: T exists: x:A. B[x] sq_exists: x:A [B[x]] prop: uall: [x:A]. B[x] subtype_rel: A ⊆B guard: {T} uimplies: supposing a so_lambda: λ2x.t[x] so_apply: x[s] geo-lsep: bc or: P ∨ Q and: P ∧ Q cand: c∧ B iff: ⇐⇒ Q rev_implies:  Q basic-geometry: BasicGeometry not: ¬A false: False
Lemmas referenced :  sq_stable__geo-lsep Euclid-erect-2perp set_wf geo-point_wf euclidean-plane-structure-subtype euclidean-plane-subtype subtype_rel_transitivity euclidean-plane_wf euclidean-plane-structure_wf geo-primitives_wf geo-lsep_wf geo-colinear_wf geo-sep_wf lsep-all-sym2 geo-left_wf geo-perp-in_wf iff_wf not-left-and-right
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut setElimination thin rename introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination hypothesisEquality hypothesis because_Cache independent_functionElimination sqequalRule imageMemberEquality baseClosed imageElimination productElimination isectElimination applyEquality instantiate independent_isectElimination lambdaEquality unionElimination dependent_set_memberFormation independent_pairFormation productEquality voidElimination

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a:Point.  \mforall{}b:\{b:Point|  a  \mneq{}  b\}  .  \mforall{}c:\{c:Point|  Colinear(a;b;c)\}  .  \mforall{}q:\{q:Point| 
                                                                                                                                                                          q  \#  ab\}  .
    (\mexists{}p:Point  [(ab    \mbot{}c  pc  \mwedge{}  p  \#  ab  \mwedge{}  (p  leftof  ab  \mLeftarrow{}{}\mRightarrow{}  q  leftof  ab))])



Date html generated: 2018_05_22-PM-00_09_27
Last ObjectModification: 2018_04_04-PM-07_08_08

Theory : euclidean!plane!geometry


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