Nuprl Lemma : real-vec-angle-lemma

∀n:ℕ. ∀x,z:ℝ^n.  (d(z;x) < d(z;r(-1)*x) ⇐⇒ r0 < x⋅z)


Proof




Definitions occuring in Statement :  real-vec-dist: d(x;y),  dot-product: x⋅y,  real-vec-mul: a*X,  real-vec: ℝ^n,  rless: x < y,  int-to-real: r(n),  nat: ℕ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  minus: -n,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  real-vec-dist: d(x;y),  real-vec-norm: ||x||,  iff: P ⇐⇒ Q,  and: P ∧ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  uiff: uiff(P;Q),  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True
Lemmas referenced :  rsqrt-rless-iff,  dot-product-nonneg,  real-vec-sub_wf,  dot-product_wf,  rleq_wf,  int-to-real_wf,  real-vec-mul_wf,  rless_wf,  rsqrt_wf,  real_wf,  req_wf,  rmul_wf,  iff_wf,  real-vec_wf,  nat_wf,  dot-product-comm,  radd_wf,  rless_functionality,  rsub_wf,  itermSubtract_wf,  itermVar_wf,  itermAdd_wf,  itermMultiply_wf,  itermConstant_wf,  req-iff-rsub-is-0,  req_transitivity,  dot-product-linearity1-sub,  rsub_functionality,  req_weakening,  dot-product-linearity2,  rmul_functionality,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_add_lemma,  real_term_value_mul_lemma,  real_term_value_const_lemma,  radd-preserves-rless,  rmul_preserves_rless,  rless-int,  rmul-zero-both,  rmul_comm
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  addLevel,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairFormation,  impliesFunctionality,  introduction,  extract_by_obid,  dependent_functionElimination,  isectElimination,  hypothesisEquality,  hypothesis,  dependent_set_memberEquality,  natural_numberEquality,  because_Cache,  minusEquality,  independent_functionElimination,  applyEquality,  sqequalRule,  lambdaEquality,  setElimination,  rename,  setEquality,  productEquality,  independent_isectElimination,  approximateComputation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  imageMemberEquality,  baseClosed

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}x,z:\mBbbR{}\^{}n.    (d(z;x)  <  d(z;r(-1)*x)  \mLeftarrow{}{}\mRightarrow{}  r0  <  x\mcdot{}z)



Date html generated: 2018_05_22-PM-02_25_51
Last ObjectModification: 2018_03_27-PM-10_36_41

Theory : reals


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