Nuprl Lemma : req-iff-rabs-rleq-bound

x,y:ℝ.  (x ⇐⇒ ∃B:ℕ+. ∀m:ℕ+(|x y| ≤ (r(B)/r(m))))


Proof




Definitions occuring in Statement :  rdiv: (x/y) rleq: x ≤ y rabs: |x| rsub: y req: y int-to-real: r(n) real: nat_plus: + all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T iff: ⇐⇒ Q and: P ∧ Q implies:  Q prop: uall: [x:A]. B[x] rev_implies:  Q so_lambda: λ2x.t[x] nat_plus: + uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top so_apply: x[s] less_than: a < b squash: T less_than': less_than'(a;b) true: True uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) rge: x ≥ y
Lemmas referenced :  req-iff-rabs-rleq req_wf nat_plus_wf exists_wf all_wf rleq_wf rabs_wf rsub_wf rdiv_wf int-to-real_wf rless-int nat_plus_properties decidable__lt full-omega-unsat intformand_wf intformnot_wf intformless_wf itermConstant_wf itermVar_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf rless_wf real_wf less_than_wf mul_nat_plus mul_bounds_1b rleq-int-fractions decidable__le intformle_wf itermMultiply_wf int_formula_prop_le_lemma int_term_value_mul_lemma rleq_functionality_wrt_implies rleq_weakening_equal
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality independent_pairFormation productElimination independent_functionElimination isectElimination sqequalRule lambdaEquality because_Cache setElimination rename independent_isectElimination inrFormation natural_numberEquality unionElimination approximateComputation dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality dependent_set_memberEquality imageMemberEquality baseClosed multiplyEquality equalityTransitivity equalitySymmetry

Latex:
\mforall{}x,y:\mBbbR{}.    (x  =  y  \mLeftarrow{}{}\mRightarrow{}  \mexists{}B:\mBbbN{}\msupplus{}.  \mforall{}m:\mBbbN{}\msupplus{}.  (|x  -  y|  \mleq{}  (r(B)/r(m))))



Date html generated: 2018_05_22-PM-01_57_53
Last ObjectModification: 2017_10_26-PM-02_20_36

Theory : reals


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