Nuprl Lemma : rational-approx-property

x:ℝ. ∀n:ℕ+.  (|x (x within 1/n)| ≤ (r1/r(n)))


Proof




Definitions occuring in Statement :  rational-approx: (x within 1/n) rdiv: (x/y) rleq: x ≤ y rabs: |x| rsub: y int-to-real: r(n) real: nat_plus: + all: x:A. B[x] natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] rational-approx: (x within 1/n) member: t ∈ T uall: [x:A]. B[x] int_nzero: -o nat_plus: + nequal: a ≠ b ∈  not: ¬A implies:  Q uimplies: supposing a satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top and: P ∧ Q prop: subtype_rel: A ⊆B real: rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q rev_implies:  Q decidable: Dec(P) uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) true: True less_than: a < b squash: T less_than': less_than'(a;b) rdiv: (x/y) itermConstant: "const" req_int_terms: t1 ≡ t2 nat:
Lemmas referenced :  nat_plus_wf real_wf rabs_wf rsub_wf int-rdiv_wf nat_plus_properties satisfiable-full-omega-tt intformand_wf intformeq_wf itermMultiply_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_eq_lemma int_term_value_mul_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf equal-wf-base int_subtype_base nequal_wf int-to-real_wf rdiv_wf rless-int decidable__lt intformnot_wf int_formula_prop_not_lemma rless_wf rmul_preserves_rleq rmul_wf radd_wf rinv_wf2 rminus_wf rleq_functionality rabs_functionality rsub_functionality req_weakening int-rdiv-req req_transitivity real_term_polynomial itermSubtract_wf real_term_value_const_lemma real_term_value_sub_lemma real_term_value_mul_lemma real_term_value_var_lemma req-iff-rsub-is-0 rmul_functionality itermAdd_wf itermMinus_wf real_term_value_add_lemma real_term_value_minus_lemma radd_functionality rminus-rdiv squash_wf true_wf rneq_wf rminus-int rmul-rinv rmul-int rmul-assoc req_wf rabs-int iff_weakening_equal req-int absval_wf nat_wf equal_wf absval_pos decidable__le intformle_wf int_formula_prop_le_lemma le_wf req_inversion rabs-rmul real-approx
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut introduction extract_by_obid hypothesis sqequalHypSubstitution isectElimination thin hypothesisEquality dependent_set_memberEquality multiplyEquality natural_numberEquality setElimination rename independent_isectElimination dependent_pairFormation lambdaEquality int_eqEquality intEquality dependent_functionElimination isect_memberEquality voidElimination voidEquality sqequalRule independent_pairFormation computeAll baseApply closedConclusion baseClosed applyEquality because_Cache inrFormation productElimination independent_functionElimination unionElimination minusEquality imageMemberEquality imageElimination equalityTransitivity equalitySymmetry universeEquality

Latex:
\mforall{}x:\mBbbR{}.  \mforall{}n:\mBbbN{}\msupplus{}.    (|x  -  (x  within  1/n)|  \mleq{}  (r1/r(n)))



Date html generated: 2017_10_03-AM-08_40_44
Last ObjectModification: 2017_07_28-AM-07_31_25

Theory : reals


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