Nuprl Lemma : rv-pos-angle-permute-lemma

∀n:ℕ. ∀x,y:ℝ^n.  ((|x⋅y| < (||x|| * ||y||)) ⇒ (|x⋅y - x| < (||x|| * ||y - x||)))


Proof




Definitions occuring in Statement :  real-vec-norm: ||x||,  dot-product: x⋅y,  real-vec-sub: X - Y,  real-vec: ℝ^n,  rless: x < y,  rabs: |x|,  rmul: a * b,  nat: ℕ,  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  and: P ∧ Q,  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  prop: ℙ,  nat: ℕ,  le: A ≤ B,  false: False,  not: ¬A,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rsub: x - y
Lemmas referenced :  square-rless-implies,  rabs_wf,  dot-product_wf,  real-vec-sub_wf,  rmul_wf,  real-vec-norm_wf,  rmul-nonneg-case1,  real-vec-norm-nonneg,  rnexp-rless,  zero-rleq-rabs,  less_than_wf,  rless_wf,  real-vec_wf,  nat_wf,  rnexp_wf,  false_wf,  le_wf,  rnexp2-nonneg,  rless_functionality,  req_inversion,  rabs-rnexp,  req_transitivity,  rnexp-rmul,  rmul_functionality,  real-vec-norm-squared,  rabs-of-nonneg,  req_weakening,  rnexp2,  rsub_wf,  dot-product-comm,  radd_wf,  int-to-real_wf,  rminus_wf,  dot-product-linearity1-sub,  rsub_functionality,  radd-ac,  radd_functionality,  radd_comm,  rminus-rminus,  radd-int,  rminus-as-rmul,  radd-assoc,  rmul-distrib2,  rminus-radd,  rminus_functionality,  rmul_comm,  rmul-distrib,  rmul_over_rminus,  radd-preserves-rless,  radd-zero-both,  rmul-zero-both,  rmul-identity1
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  hypothesisEquality,  hypothesis,  independent_functionElimination,  independent_isectElimination,  independent_pairFormation,  because_Cache,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  imageMemberEquality,  baseClosed,  productElimination,  minusEquality,  addEquality,  addLevel,  levelHypothesis

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}x,y:\mBbbR{}\^{}n.    ((|x\mcdot{}y|  <  (||x||  *  ||y||))  {}\mRightarrow{}  (|x\mcdot{}y  -  x|  <  (||x||  *  ||y  -  x||)))



Date html generated: 2017_10_03-AM-10_57_36
Last ObjectModification: 2017_03_02-AM-10_57_59

Theory : reals


Home Index