Nuprl Lemma : unit-ball-to-unit-cube
∀n:ℕ+
  ∃g:ℝ^n ⟶ ℝ^n
   ((∀p:ℝ^n. (req-vec(n;p;λi.r0) 
⇒ g p ≡ λi.r0))
   ∧ (∀p:{p:ℝ^n| r0 < mdist(max-metric(n);λi.r0;p)} . g p ≡ (λp.(||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: ℝ^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: a * b
, 
int-to-real: r(n)
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
lambda: λx.A[x]
, 
function: x:A ⟶ B[x]
, 
multiply: n * m
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
real-vec: ℝ^n
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
and: P ∧ Q
, 
le: A ≤ B
, 
nat_plus: ℕ+
, 
subtype_rel: A ⊆r B
, 
metric-leq: d1 ≤ d2
, 
rn-metric: rn-metric(n)
, 
mdist: mdist(d;x;y)
, 
nat: ℕ
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
scale-metric: c*d
, 
rless: x < y
, 
sq_exists: ∃x:A [B[x]]
, 
guard: {T}
, 
req_int_terms: t1 ≡ t2
, 
rneq: x ≠ y
, 
less_than': less_than'(a;b)
, 
rdiv: (x/y)
, 
rge: x ≥ y
, 
real: ℝ
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
true: True
, 
meq: x ≡ y
, 
label: ...$L... t
, 
stable: Stable{P}
, 
cand: A 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 b then t else f fi 
, 
isEven: isEven(n)
, 
eq_int: (i =z j)
, 
modulus: a mod n
, 
remainder: n rem m
, 
btrue: tt
, 
rroot-abs: rroot-abs(i;x)
, 
fastexp: i^n
, 
efficient-exp-ext, 
genrec: genrec, 
subtract: n - 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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