Nuprl Lemma : Minkowski-equality

∀n:ℕ. ∀x,y:ℝ^n.
  ((r0 < ||y||) ⇒ (||x + y|| = (||x|| + ||y||)) ⇒ (∃t:ℝ. ((r0 ≤ t) ∧ req-vec(n;x;t*y) ∧ ((r0 < ||x||) ⇒ (r0 < t)))))


Proof




Definitions occuring in Statement :  real-vec-norm: ||x||,  real-vec-mul: a*X,  real-vec-add: X + Y,  req-vec: req-vec(n;x;y),  real-vec: ℝ^n,  rleq: x ≤ y,  rless: x < y,  req: x = y,  radd: a + b,  int-to-real: r(n),  real: ℝ,  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  not: ¬A,  prop: ℙ,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  top: Top,  uiff: uiff(P;Q),  uimplies: b supposing a,  rev_uimplies: rev_uimplies(P;Q),  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  true: True,  exists: ∃x:A. B[x],  cand: A c∧ B,  rdiv: (x/y)
Lemmas referenced :  rnexp-positive,  real-vec-norm_wf,  false_wf,  le_wf,  req_wf,  real-vec-add_wf,  radd_wf,  rless_wf,  int-to-real_wf,  real-vec_wf,  nat_wf,  rnexp_wf,  dot-product_wf,  rmul_wf,  dot-product-comm,  real_term_polynomial,  itermSubtract_wf,  itermAdd_wf,  itermVar_wf,  itermMultiply_wf,  itermConstant_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_add_lemma,  real_term_value_var_lemma,  real_term_value_mul_lemma,  req-iff-rsub-is-0,  req_functionality,  req_transitivity,  real-vec-norm-squared,  dot-product-linearity1,  radd_functionality,  req_weakening,  rmul_functionality,  radd-preserves-req,  rminus_wf,  rnexp_functionality,  rnexp2,  itermMinus_wf,  real_term_value_minus_lemma,  rmul_preserves_req,  rless-int,  req_inversion,  rabs_wf,  rmul-nonneg-case1,  real-vec-norm-nonneg,  rabs-of-nonneg,  rleq_functionality,  rdiv_wf,  rmul_preserves_rleq,  rmul_preserves_rless,  rleq_wf,  req-vec_wf,  real-vec-mul_wf,  rinv_wf2,  rmul-rinv,  rless_functionality,  rmul-is-positive
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  hypothesisEquality,  hypothesis,  independent_functionElimination,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  because_Cache,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  productElimination,  independent_isectElimination,  inrFormation,  imageMemberEquality,  baseClosed,  dependent_pairFormation,  productEquality,  functionEquality,  inlFormation

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}x,y:\mBbbR{}\^{}n.
    ((r0  <  ||y||)
    {}\mRightarrow{}  (||x  +  y||  =  (||x||  +  ||y||))
    {}\mRightarrow{}  (\mexists{}t:\mBbbR{}.  ((r0  \mleq{}  t)  \mwedge{}  req-vec(n;x;t*y)  \mwedge{}  ((r0  <  ||x||)  {}\mRightarrow{}  (r0  <  t)))))



Date html generated: 2017_10_03-AM-10_55_22
Last ObjectModification: 2017_07_28-AM-08_20_58

Theory : reals


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