Nuprl Lemma : approx-root-property

k:{2...}. ∀a:{a:ℚ(0 ≤ a) ∨ (↑isOdd(k))} . ∀n:ℕ+.
  ((0 ≤ ⇐⇒ 0 ≤ k-th root(a) within 1/n) ∧ |k-th root(a) within 1/n ↑ 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: s qdiv: (r/s) rationals: isOdd: isOdd(n) int_upper: {i...} nat_plus: + assert: b all: x:A. B[x] iff: ⇐⇒ 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 ⊆B uall: [x:A]. B[x] int_upper: {i...} or: P ∨ Q prop: so_lambda: λ2x.t[x] and: P ∧ Q iff: ⇐⇒ Q rev_implies:  Q implies:  Q uimplies: supposing a le: A ≤ B less_than': less_than'(a;b) false: False not: ¬A nat_plus: + so_apply: x[s] int_nzero: -o nequal: a ≠ b ∈  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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