Nuprl Lemma : real-vec-norm-equal-iff

∀[n:ℕ]. ∀[x,y:ℝ^n].  uiff(||x|| = ||y||;x⋅x = y⋅y)


Proof




Definitions occuring in Statement :  real-vec-norm: ||x||,  dot-product: x⋅y,  real-vec: ℝ^n,  req: x = y,  nat: ℕ,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x]
Definitions unfolded in proof :  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rleq: x ≤ y,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  subtype_rel: A ⊆r B,  real: ℝ
Lemmas referenced :  iff_weakening_uiff,  req_wf,  real-vec-norm_wf,  dot-product_wf,  rnexp_wf,  false_wf,  le_wf,  rleq_wf,  int-to-real_wf,  real-vec-norm-eq-iff,  req_witness,  uiff_wf,  real-vec_wf,  nat_wf,  real-vec-norm-nonneg,  less_than'_wf,  rsub_wf,  real_wf,  nat_plus_wf,  req_functionality,  req_weakening,  real-vec-norm-squared
Rules used in proof :  cut,  addLevel,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  productElimination,  thin,  independent_pairFormation,  isect_memberFormation,  introduction,  independent_isectElimination,  extract_by_obid,  isectElimination,  hypothesisEquality,  hypothesis,  productEquality,  because_Cache,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  lambdaFormation,  independent_functionElimination,  cumulativity,  independent_pairEquality,  isect_memberEquality,  equalityTransitivity,  equalitySymmetry,  lambdaEquality,  dependent_functionElimination,  voidElimination,  applyEquality,  setElimination,  rename,  minusEquality,  axiomEquality,  universeEquality

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[x,y:\mBbbR{}\^{}n].    uiff(||x||  =  ||y||;x\mcdot{}x  =  y\mcdot{}y)



Date html generated: 2017_10_03-AM-10_49_37
Last ObjectModification: 2017_06_08-PM-06_52_00

Theory : reals


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