Nuprl Lemma : rv-norm-triangle-inequality2

∀[rv:InnerProductSpace]. ∀[x,y,z:Point].  (||x - z|| ≤ (||x - y|| + ||y - z||))


Proof




Definitions occuring in Statement :  rv-norm: ||x||,  rv-sub: x - y,  inner-product-space: InnerProductSpace,  ss-point: Point,  rleq: x ≤ y,  radd: a + b,  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  rv-sub: x - y,  uiff: uiff(P;Q),  rge: x ≥ y,  rev_uimplies: rev_uimplies(P;Q),  uimplies: b supposing a,  guard: {T},  prop: ℙ,  subtype_rel: A ⊆r B,  false: False,  implies: P ⇒ Q,  not: ¬A,  and: P ∧ Q,  le: A ≤ B,  all: ∀x:A. B[x],  rnonneg: rnonneg(x),  rleq: x ≤ y,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  rv-0-add,  rv-add-minus,  rv-add_functionality,  ss-eq_inversion,  ss-eq_transitivity,  uiff_transitivity,  rv-add-assoc,  ss-eq_functionality,  ss-eq_weakening,  rv-0_wf,  ss-eq_wf,  rv-add-cancel-right,  rv-minus_wf,  rv-norm_functionality,  req_weakening,  rleq_functionality,  rv-norm-triangle-inequality,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  rv-add_wf,  separation-space_wf,  real-vector-space_wf,  inner-product-space_wf,  subtype_rel_transitivity,  real-vector-space_subtype1,  ss-point_wf,  nat_plus_wf,  rv-ip_wf,  rmul_wf,  req_wf,  int-to-real_wf,  rleq_wf,  real_wf,  inner-product-space_subtype,  rv-sub_wf,  rv-norm_wf,  radd_wf,  rsub_wf,  less_than'_wf
Rules used in proof :  independent_functionElimination,  voidElimination,  isect_memberEquality,  independent_isectElimination,  instantiate,  equalitySymmetry,  equalityTransitivity,  axiomEquality,  minusEquality,  natural_numberEquality,  productEquality,  setEquality,  rename,  setElimination,  hypothesis,  applyEquality,  isectElimination,  extract_by_obid,  because_Cache,  independent_pairEquality,  productElimination,  hypothesisEquality,  thin,  dependent_functionElimination,  lambdaEquality,  sqequalHypSubstitution,  sqequalRule,  cut,  introduction,  isect_memberFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}[rv:InnerProductSpace].  \mforall{}[x,y,z:Point].    (||x  -  z||  \mleq{}  (||x  -  y||  +  ||y  -  z||))



Date html generated: 2016_11_08-AM-09_17_31
Last ObjectModification: 2016_11_01-PM-05_50_51

Theory : inner!product!spaces


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