Nuprl Lemma : unit-ball-to-unit-cube

n:ℕ+
  ∃g:ℝ^n ⟶ ℝ^n
   ((∀p:ℝ^n. (req-vec(n;p;λi.r0)  p ≡ λi.r0))
   ∧ (∀p:{p:ℝ^n| r0 < mdist(max-metric(n);λi.r0;p)} p ≡ p.(||p||/mdist(max-metric(n);p;λi.r0))*p) p)
   ∧ (g ∈ {p:ℝ^n| ||p|| ≤ r1}  ⟶ {q:ℝ^n| mdist(max-metric(n);λi.r0;q) ≤ r1} )
   ∧ g:FUN(ℝ^n;ℝ^n)
   ∧ (∀x,y:{p:ℝ^n| ||p|| ≤ r1} .  (mdist(max-metric(n);g x;g y) ≤ (r((2 n) 1) mdist(rn-metric(n);x;y)))))


Proof




Definitions occuring in Statement :  max-metric: max-metric(n) rn-metric: rn-metric(n) real-vec-norm: ||x|| real-vec-mul: a*X req-vec: req-vec(n;x;y) real-vec: ^n is-mfun: f:FUN(X;Y) mdist: mdist(d;x;y) meq: x ≡ y rdiv: (x/y) rleq: x ≤ y rless: x < y rmul: b int-to-real: r(n) nat_plus: + all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q member: t ∈ T set: {x:A| B[x]}  apply: a lambda: λx.A[x] function: x:A ⟶ B[x] multiply: m add: m natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] real-vec: ^n member: t ∈ T uall: [x:A]. B[x] int_seg: {i..j-} lelt: i ≤ j < k and: P ∧ Q le: A ≤ B nat_plus: + subtype_rel: A ⊆B metric-leq: d1 ≤ d2 rn-metric: rn-metric(n) mdist: mdist(d;x;y) nat: decidable: Dec(P) or: P ∨ Q uimplies: supposing a not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top prop: uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) iff: ⇐⇒ Q rev_implies:  Q scale-metric: c*d rless: x < y sq_exists: x:A [B[x]] guard: {T} req_int_terms: t1 ≡ t2 rneq: x ≠ y less_than': less_than'(a;b) rdiv: (x/y) rge: x ≥ y real: sq_stable: SqStable(P) squash: T true: True meq: x ≡ y label: ...$L... t stable: Stable{P} cand: c∧ B so_lambda: λ2x.t[x] so_apply: x[s] is-mfun: f:FUN(X;Y) real-vec-dist: d(x;y) real-vec-norm: ||x|| rsqrt: rsqrt(x) rroot: rroot(i;x) ifthenelse: if then else fi  isEven: isEven(n) eq_int: (i =z j) modulus: mod n remainder: rem m btrue: tt rroot-abs: rroot-abs(i;x) fastexp: i^n efficient-exp-ext genrec: genrec subtract: m rat_term_to_real: rat_term_to_real(f;t) rtermMultiply: left "*" right rat_term_ind: rat_term_ind rtermDivide: num "/" denom rtermSubtract: left "-" right rtermVar: rtermVar(var) rtermConstant: "const" pi1: fst(t) pi2: snd(t) sq_type: SQType(T) respects-equality: respects-equality(S;T)
Lemmas referenced :  int-to-real_wf int_seg_wf max-metric-leq-rn-metric nat_plus_subtype_nat rn-metric-leq-max-metric nat_plus_wf real-vec-dist_wf nat_plus_properties decidable__le full-omega-unsat intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf istype-int int_formula_prop_and_lemma istype-void int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf istype-le real-vec-norm_wf real-vec-dist-from-zero req_functionality real-vec-dist-symmetry req_weakening mdist_wf real-vec_wf rn-metric_wf scale-metric_wf rleq-int rleq_wf max-metric_wf rmul_preserves_rless rless-int decidable__lt rless_wf rless_transitivity1 rmul_wf itermSubtract_wf itermMultiply_wf rleq_functionality rless_functionality req-iff-rsub-is-0 real_polynomial_null real_term_value_sub_lemma real_term_value_mul_lemma real_term_value_const_lemma real_term_value_var_lemma real-vec-mul_wf rdiv_wf remove-singularity-max-mfun mul_bounds_1a multiply_nat_wf rn-metric-complete rless-implies-rless rsub_wf rabs_wf mdist-symm mdist-rn-metric-mul rmul_functionality rabs-of-nonneg rmul_preserves_rleq rinv_wf2 real-vec-norm-nonneg req_transitivity rmul-rinv req_inversion rmul-int rinv-mul-as-rdiv rmul_preserves_rleq2 rleq_functionality_wrt_implies rleq_weakening_equal sq_stable__less_than rleq_weakening squash_wf true_wf real_wf subtype_rel_self iff_weakening_equal rmul-rinv3 rmul-nonneg-case1 istype-false stable__rleq false_wf not_wf not-rless meq-max-metric rleq_antisymmetry mdist-nonneg meq-max-metric-iff-meq-rn-metric minimal-double-negation-hyp-elim minimal-not-not-excluded-middle mdist_functionality meq_weakening mdist-same mdist-max-metric-mul rleq_transitivity req-vec_wf subtype_rel_dep_function subtype_rel_sets_simple meq_wf real-vec-dist-identity req-vec_weakening meq-same req-vec_functionality real-vec-mul_functionality rdiv_functionality real-vec-norm_functionality rn-metric-meq real-vec-norm-diff-bound mdist-triangle-inequality metric-on-subtype radd_wf radd_functionality rabs-difference-bound-rleq rleq-implies-rleq radd_comm_eq itermAdd_wf real_term_value_add_lemma sq_stable__rleq r-triangle-inequality2 rleq_weakening_rless rabs_functionality rsub-rdiv rneq_functionality rabs-rdiv assert-rat-term-eq2 rtermSubtract_wf rtermDivide_wf rtermVar_wf rtermMultiply_wf rtermConstant_wf rabs-rmul rminus_wf itermMinus_wf real_term_value_minus_lemma rsub_functionality rmul-assoc rabs-difference-symmetry rmul_functionality_wrt_rleq2 zero-rleq-rabs radd_functionality_wrt_rleq radd-int mdist-max-metric-mul2 subtype_base_sq int_subtype_base decidable__equal_int intformeq_wf int_formula_prop_eq_lemma int_term_value_add_lemma int_term_value_mul_lemma rmul-distrib mdist-max-metric-mul-rleq req-vec_inversion radd-preserves-rleq radd-non-neg respects-equality-function respects-equality-set-trivial is-mfun_wf efficient-exp-ext
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut sqequalRule lambdaEquality_alt introduction extract_by_obid sqequalHypSubstitution isectElimination thin setElimination rename productElimination hypothesis universeIsType natural_numberEquality hypothesisEquality applyEquality because_Cache dependent_functionElimination equalityTransitivity equalitySymmetry inhabitedIsType dependent_set_memberEquality_alt unionElimination independent_isectElimination approximateComputation independent_functionElimination dependent_pairFormation_alt int_eqEquality isect_memberEquality_alt voidElimination independent_pairFormation inrFormation_alt setIsType multiplyEquality closedConclusion functionIsType equalityIstype promote_hyp addEquality imageMemberEquality baseClosed imageElimination instantiate universeEquality functionExtensionality setEquality unionEquality functionEquality unionIsType productIsType productEquality minusEquality inlFormation_alt cumulativity intEquality

Latex:
\mforall{}n:\mBbbN{}\msupplus{}
    \mexists{}g:\mBbbR{}\^{}n  {}\mrightarrow{}  \mBbbR{}\^{}n
      ((\mforall{}p:\mBbbR{}\^{}n.  (req-vec(n;p;\mlambda{}i.r0)  {}\mRightarrow{}  g  p  \mequiv{}  \mlambda{}i.r0))
      \mwedge{}  (\mforall{}p:\{p:\mBbbR{}\^{}n|  r0  <  mdist(max-metric(n);\mlambda{}i.r0;p)\} 
                g  p  \mequiv{}  (\mlambda{}p.(||p||/mdist(max-metric(n);p;\mlambda{}i.r0))*p)  p)
      \mwedge{}  (g  \mmember{}  \{p:\mBbbR{}\^{}n|  ||p||  \mleq{}  r1\}    {}\mrightarrow{}  \{q:\mBbbR{}\^{}n|  mdist(max-metric(n);\mlambda{}i.r0;q)  \mleq{}  r1\}  )
      \mwedge{}  g:FUN(\mBbbR{}\^{}n;\mBbbR{}\^{}n)
      \mwedge{}  (\mforall{}x,y:\{p:\mBbbR{}\^{}n|  ||p||  \mleq{}  r1\}  .
                (mdist(max-metric(n);g  x;g  y)  \mleq{}  (r((2  *  n)  +  1)  *  mdist(rn-metric(n);x;y)))))



Date html generated: 2019_10_30-AM-11_25_49
Last ObjectModification: 2019_07_08-PM-04_55_28

Theory : real!vectors


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