Nuprl Lemma : geo-zero-length-iff

∀e:BasicGeometry. ∀a,b:Point.  (|ab| = 0 ∈ Length ⇐⇒ a ≡ b)


Proof




Definitions occuring in Statement :  geo-length: |s|,  geo-zero-length: 0,  geo-length-type: Length,  geo-mk-seg: ab,  basic-geometry: BasicGeometry,  geo-eq: a ≡ b,  geo-point: Point,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  equal: s = t ∈ T
Definitions unfolded in proof :  uimplies: b supposing a,  guard: {T},  subtype_rel: A ⊆r B,  rev_implies: P ⇐ Q,  basic-geometry: BasicGeometry,  uall: ∀[x:A]. B[x],  prop: ℙ,  member: t ∈ T,  implies: P ⇒ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  all: ∀x:A. B[x],  top: Top,  geo-length: |s|,  geo-zero-length: 0,  cand: A c∧ B,  so_apply: x[s],  so_lambda: λ2x.t[x],  quotient: x,y:A//B[x; y],  geo-length-type: Length,  squash: ↓T,  sq_stable: SqStable(P),  so_apply: x[s1;s2],  so_lambda: λ2x y.t[x; y]
Lemmas referenced :  geo-point_wf,  Error :basic-geo-primitives_wf,  Error :basic-geo-structure_wf,  basic-geometry_wf,  subtype_rel_transitivity,  basic-geometry-subtype,  geo-eq_wf,  geo-zero-length_wf,  geo-mk-seg_wf,  geo-length_wf,  geo-length-type_wf,  equal_wf,  geo_seg2_mk_seg_lemma,  geo_seg1_mk_seg_lemma,  geo-between-trivial,  geo-congruent_wf,  subtype_rel_sets,  geo-sep_wf,  geo-sep-O-X,  geo-X_wf,  geo-O_wf,  geo-between_wf,  member_wf,  sq_stable__geo-eq,  set_wf,  geo-Op-sep,  geo-extend-property,  geo-congruence-identity,  geo-congruent_functionality,  geo-eq_weakening,  geo-between_functionality,  geo-length-equiv,  quotient-member-eq,  geo-congruence-identity-sym,  geo-eq_inversion
Rules used in proof :  because_Cache,  sqequalRule,  independent_isectElimination,  instantiate,  applyEquality,  rename,  setElimination,  hypothesis,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  independent_pairFormation,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  voidEquality,  voidElimination,  isect_memberEquality,  dependent_functionElimination,  equalitySymmetry,  equalityTransitivity,  productElimination,  lambdaEquality,  dependent_set_memberEquality,  setEquality,  productEquality,  pertypeElimination,  imageElimination,  baseClosed,  imageMemberEquality,  independent_functionElimination,  promote_hyp

Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b:Point.    (|ab|  =  0  \mLeftarrow{}{}\mRightarrow{}  a  \mequiv{}  b)



Date html generated: 2017_10_02-PM-04_53_08
Last ObjectModification: 2017_08_05-AM-09_10_39

Theory : euclidean!plane!geometry


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