Nuprl Lemma : infinitesmal-difference

[x,y:ℝ].  uiff(x y;∀[k:ℕ+]. (|x y| ≤ (r1/r(k))))


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: + uiff: uiff(P;Q) uall: [x:A]. B[x] natural_number: $n
Definitions unfolded in proof :  uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a member: t ∈ T rev_implies:  Q uall: [x:A]. B[x] so_lambda: λ2x.t[x] nat_plus: + rneq: x ≠ y guard: {T} or: P ∨ Q all: x:A. B[x] iff: ⇐⇒ Q implies:  Q decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False not: ¬A top: Top prop: so_apply: x[s] rleq: x ≤ y rnonneg: rnonneg(x) le: A ≤ B subtype_rel: A ⊆B itermConstant: "const" req_int_terms: t1 ≡ t2
Lemmas referenced :  iff_weakening_uiff uall_wf nat_plus_wf rleq_wf rabs_wf rsub_wf rdiv_wf int-to-real_wf rless-int nat_plus_properties decidable__lt satisfiable-full-omega-tt 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 req_wf infinitesmal-zero less_than'_wf req_witness uiff_wf real_wf req-implies-req real_term_polynomial itermSubtract_wf real_term_value_const_lemma real_term_value_sub_lemma real_term_value_var_lemma req-iff-rsub-is-0
Rules used in proof :  cut addLevel sqequalHypSubstitution sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity productElimination thin independent_pairFormation isect_memberFormation introduction independent_isectElimination hypothesis extract_by_obid isectElimination sqequalRule lambdaEquality hypothesisEquality natural_numberEquality setElimination rename because_Cache inrFormation dependent_functionElimination independent_functionElimination unionElimination dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality computeAll independent_pairEquality applyEquality minusEquality cumulativity universeEquality axiomEquality equalityTransitivity equalitySymmetry

Latex:
\mforall{}[x,y:\mBbbR{}].    uiff(x  =  y;\mforall{}[k:\mBbbN{}\msupplus{}].  (|x  -  y|  \mleq{}  (r1/r(k))))



Date html generated: 2017_10_03-AM-08_52_14
Last ObjectModification: 2017_07_28-AM-07_35_04

Theory : reals


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