Nuprl Lemma : approx-root-property

∀k:{2...}. ∀a:{a:ℚ| (0 ≤ a) ∨ (↑isOdd(k))} . ∀n:ℕ+.
  ((0 ≤ a ⇐⇒ 0 ≤ k-th root(a) within 1/n) ∧ |k-th root(a) within 1/n ↑ k - a| < (1/n))


Proof




Definitions occuring in Statement :  approx-root: k-th root(q) within 1/err,  qexp: r ↑ n,  qabs: |r|,  qle: r ≤ s,  qless: r < s,  qsub: r - s,  qdiv: (r/s),  rationals: ℚ,  isOdd: isOdd(n),  int_upper: {i...},  nat_plus: ℕ+,  assert: ↑b,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  or: P ∨ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  approx-root: k-th root(q) within 1/err,  member: t ∈ T,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  int_upper: {i...},  or: P ∨ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  and: P ∧ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  uimplies: b supposing a,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  nat_plus: ℕ+,  so_apply: x[s],  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  guard: {T},  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  sq_exists: ∃x:A [B[x]],  sq_stable: SqStable(P),  squash: ↓T
Lemmas referenced :  qroot-ext,  subtype_rel_self,  int_upper_wf,  all_wf,  rationals_wf,  or_wf,  qle_wf,  assert_wf,  isOdd_wf,  nat_plus_wf,  sq_exists_wf,  iff_wf,  qless_wf,  qabs_wf,  qsub_wf,  qexp_wf,  upper_subtype_nat,  qdiv_wf,  subtype_rel_set,  less_than_wf,  int-subtype-rationals,  int_nzero-rational,  subtype_rel_sets,  nequal_wf,  int_upper_properties,  full-omega-unsat,  intformand_wf,  intformeq_wf,  itermVar_wf,  itermConstant_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_eq_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  equal-wf-base,  int_subtype_base,  equal_wf,  set_wf,  squash_wf,  sq_stable__and,  sq_stable__iff,  sq_stable_from_decidable,  decidable__qle,  decidable__qless,  qless_witness
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  applyEquality,  thin,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  introduction,  sqequalHypSubstitution,  isectElimination,  functionEquality,  natural_numberEquality,  setEquality,  because_Cache,  hypothesisEquality,  setElimination,  rename,  lambdaEquality,  productEquality,  independent_isectElimination,  independent_pairFormation,  intEquality,  productElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation,  int_eqEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  baseClosed,  dependent_set_memberEquality,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  imageElimination

Latex:
\mforall{}k:\{2...\}.  \mforall{}a:\{a:\mBbbQ{}|  (0  \mleq{}  a)  \mvee{}  (\muparrow{}isOdd(k))\}  .  \mforall{}n:\mBbbN{}\msupplus{}.
    ((0  \mleq{}  a  \mLeftarrow{}{}\mRightarrow{}  0  \mleq{}  k-th  root(a)  within  1/n)  \mwedge{}  |k-th  root(a)  within  1/n  \muparrow{}  k  -  a|  <  (1/n))



Date html generated: 2018_05_22-AM-00_29_01
Last ObjectModification: 2018_05_19-PM-04_09_13

Theory : rationals


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