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: Y req-vec: req-vec(n;x;y) real-vec: ^n rleq: x ≤ y rless: x < y req: y radd: b int-to-real: r(n) real: nat: all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q member: t ∈ T uall: [x:A]. B[x] nat: le: A ≤ B and: P ∧ Q less_than': less_than'(a;b) false: False not: ¬A prop: itermConstant: "const" req_int_terms: t1 ≡ t2 top: Top uiff: uiff(P;Q) uimplies: supposing a rev_uimplies: rev_uimplies(P;Q) rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q less_than: a < b squash: T true: True exists: x:A. B[x] cand: 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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