Nuprl Lemma : colinear-equidistant-points-exist

e:EuclideanPlane. ∀a:Point. ∀b:{b:Point| a ≠ b} . ∀c:Point.
  ∃u,v:Point. (Colinear(a;b;u) ∧ Colinear(a;b;v) ∧ u ≠ v ∧ cu ≅ cv)


Proof




Definitions occuring in Statement :  euclidean-plane: EuclideanPlane geo-colinear: Colinear(a;b;c) geo-congruent: ab ≅ cd geo-sep: a ≠ b geo-point: Point all: x:A. B[x] exists: x:A. B[x] and: P ∧ Q set: {x:A| B[x]} 
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T euclidean-plane: EuclideanPlane or: P ∨ Q sq_stable: SqStable(P) implies:  Q squash: T basic-geometry: BasicGeometry exists: x:A. B[x] and: P ∧ Q geo-midpoint: a=m=b uall: [x:A]. B[x] uimplies: supposing a cand: c∧ B 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: less_than: a < b true: True select: L[n] cons: [a b] subtract: m uiff: uiff(P;Q) subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] guard: {T}
Lemmas referenced :  geo-sep-or sq_stable__geo-sep geo-sep-sym symmetric-point-construction use-SC geo-congruent-symmetry geo-congruent-sep geo-colinear-is-colinear-set geo-between-implies-colinear length_of_cons_lemma length_of_nil_lemma false_wf lelt_wf geo-congruent-iff-length geo-colinear_wf geo-sep_wf geo-congruent_wf exists_wf geo-point_wf euclidean-plane-structure-subtype euclidean-plane-subtype subtype_rel_transitivity euclidean-plane_wf euclidean-plane-structure_wf geo-primitives_wf set_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin setElimination rename hypothesisEquality hypothesis unionElimination independent_functionElimination because_Cache sqequalRule imageMemberEquality baseClosed imageElimination productElimination isectElimination independent_isectElimination dependent_pairFormation isect_memberEquality voidElimination voidEquality dependent_set_memberEquality natural_numberEquality independent_pairFormation equalityTransitivity equalitySymmetry productEquality applyEquality lambdaEquality instantiate

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a:Point.  \mforall{}b:\{b:Point|  a  \mneq{}  b\}  .  \mforall{}c:Point.
    \mexists{}u,v:Point.  (Colinear(a;b;u)  \mwedge{}  Colinear(a;b;v)  \mwedge{}  u  \mneq{}  v  \mwedge{}  cu  \mcong{}  cv)



Date html generated: 2018_05_22-PM-00_08_29
Last ObjectModification: 2018_04_04-PM-05_44_13

Theory : euclidean!plane!geometry


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