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: ⇐⇒ Q equal: t ∈ T
Definitions unfolded in proof :  uimplies: supposing a guard: {T} subtype_rel: A ⊆B rev_implies:  Q basic-geometry: BasicGeometry uall: [x:A]. B[x] prop: member: t ∈ T implies:  Q and: P ∧ Q iff: ⇐⇒ Q all: x:A. B[x] top: Top geo-length: |s| geo-zero-length: 0 cand: 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: λ2y.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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