Nuprl Lemma : eu-eq-x-implies-eq

∀e:EuclideanPlane. ∀a,b:Point.  ((X = |ab| ∈ {p:Point| O_X_p} ) ⇒ (a = b ∈ Point))


Proof




Definitions occuring in Statement :  eu-length: |s|,  eu-mk-seg: ab,  euclidean-plane: EuclideanPlane,  eu-between-eq: a_b_c,  eu-X: X,  eu-O: O,  eu-point: Point,  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  euclidean-plane: EuclideanPlane,  eu-length: |s|,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  top: Top,  squash: ↓T,  true: True
Lemmas referenced :  eu-segment_wf,  and_wf,  euclidean-structure_wf,  true_wf,  squash_wf,  eu-congruent-iff-length,  eu_seg1_mk_seg_lemma,  eu_seg2_mk_seg_lemma,  eu-congruence-identity-sym,  eu-not-colinear-OXY,  eu-seg2_wf,  eu-seg1_wf,  eu-extend-equal-iff-congruent,  iff_weakening_equal,  eu-length-null-segment,  euclidean-plane_wf,  eu-mk-seg_wf,  eu-length_wf,  eu-between-eq-trivial-right,  eu-X_wf,  eu-O_wf,  eu-between-eq_wf,  eu-point_wf,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  hypothesis,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setEquality,  setElimination,  rename,  hypothesisEquality,  because_Cache,  dependent_functionElimination,  dependent_set_memberEquality,  equalityEquality,  applyEquality,  lambdaEquality,  sqequalRule,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  productElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_pairFormation

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b:Point.    ((X  =  |ab|)  {}\mRightarrow{}  (a  =  b))



Date html generated: 2016_05_18-AM-06_44_00
Last ObjectModification: 2016_01_16-PM-10_28_53

Theory : euclidean!geometry


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