Nuprl Lemma : real-vec-triangle-inequality

∀[n:ℕ]. ∀[x,y,z:ℝ^n].  (d(x;z) ≤ (d(x;y) + d(y;z)))


Proof




Definitions occuring in Statement :  real-vec-dist: d(x;y),  real-vec: ℝ^n,  rleq: x ≤ y,  radd: a + b,  nat: ℕ,  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  real-vec-dist: d(x;y),  rleq: x ≤ y,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  implies: P ⇒ Q,  false: False,  subtype_rel: A ⊆r B,  prop: ℙ,  real: ℝ,  rev_uimplies: rev_uimplies(P;Q),  uimplies: b supposing a,  rge: x ≥ y,  guard: {T},  req-vec: req-vec(n;x;y),  real-vec-sub: X - Y,  real-vec-add: X + Y,  nat: ℕ,  real-vec: ℝ^n,  rsub: x - y,  uiff: uiff(P;Q)
Lemmas referenced :  less_than'_wf,  rsub_wf,  radd_wf,  real-vec-dist_wf,  real_wf,  rleq_wf,  int-to-real_wf,  nat_plus_wf,  real-vec_wf,  nat_wf,  real-vec-norm_wf,  real-vec-sub_wf,  real-vec-add_wf,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  Minkowski-inequality1,  real-vec-norm_functionality,  int_seg_wf,  req_wf,  rminus_wf,  req_weakening,  uiff_transitivity,  req_functionality,  req_inversion,  radd-assoc,  radd_functionality,  radd-ac,  radd-rminus-assoc,  rleq_weakening
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  sqequalHypSubstitution,  lambdaEquality,  dependent_functionElimination,  thin,  hypothesisEquality,  productElimination,  independent_pairEquality,  because_Cache,  extract_by_obid,  isectElimination,  applyEquality,  hypothesis,  setElimination,  rename,  setEquality,  natural_numberEquality,  minusEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality,  voidElimination,  independent_isectElimination,  lambdaFormation,  independent_functionElimination

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[x,y,z:\mBbbR{}\^{}n].    (d(x;z)  \mleq{}  (d(x;y)  +  d(y;z)))



Date html generated: 2016_10_26-AM-10_27_25
Last ObjectModification: 2016_09_14-PM-06_48_45

Theory : reals


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