Nuprl Lemma : qsqrt-property

∀[r:{r:ℚ| 0 ≤ r} ]. ∀[n:ℕ+].  |(qsqrt(r;n) * qsqrt(r;n)) - r| < (1/n)


Proof




Definitions occuring in Statement :  qsqrt: qsqrt(r;n),  qabs: |r|,  qle: r ≤ s,  qless: r < s,  qsub: r - s,  qdiv: (r/s),  qmul: r * s,  rationals: ℚ,  nat_plus: ℕ+,  uall: ∀[x:A]. B[x],  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  qsqrt: qsqrt(r;n),  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  prop: ℙ,  so_lambda: λ2x.t[x],  and: P ∧ Q,  nat_plus: ℕ+,  so_apply: x[s],  uimplies: b supposing a,  int_nzero: ℤ-o,  implies: P ⇒ Q,  nequal: a ≠ b ∈ T ,  not: ¬A,  false: False,  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 :  approximate-qsqrt-ext,  subtype_rel_self,  rationals_wf,  qle_wf,  all_wf,  nat_plus_wf,  sq_exists_wf,  qless_wf,  qabs_wf,  qsub_wf,  qmul_wf,  qdiv_wf,  subtype_rel_set,  less_than_wf,  int-subtype-rationals,  int_nzero-rational,  subtype_rel_sets,  nequal_wf,  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,  qless_witness,  qsqrt_wf,  set_wf,  sq_stable_from_decidable,  decidable__qless
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  applyEquality,  thin,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  sqequalHypSubstitution,  isectElimination,  functionEquality,  setEquality,  natural_numberEquality,  because_Cache,  hypothesisEquality,  lambdaFormation,  setElimination,  rename,  lambdaEquality,  productEquality,  dependent_functionElimination,  intEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation,  int_eqEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  baseClosed,  equalityTransitivity,  equalitySymmetry,  productElimination,  imageMemberEquality,  imageElimination

Latex:
\mforall{}[r:\{r:\mBbbQ{}|  0  \mleq{}  r\}  ].  \mforall{}[n:\mBbbN{}\msupplus{}].    |(qsqrt(r;n)  *  qsqrt(r;n))  -  r|  <  (1/n)



Date html generated: 2018_05_22-AM-00_30_29
Last ObjectModification: 2018_05_19-PM-04_10_06

Theory : rationals


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