Nuprl Lemma : approx-in-interval_wf

l:ℝ. ∀u:{u:ℝl ≤ u} . ∀x:{x:ℝx ∈ [l, u]} . ∀n:ℕ+.
  (approx-in-interval(l;u;x;n) ∈ {y:ℝ(y ∈ [l, u]) ∧ (|x y| ≤ (r(2)/r(n)))} )


Proof




Definitions occuring in Statement :  approx-in-interval: approx-in-interval(l;u;x;n) rccint: [l, u] i-member: r ∈ I rdiv: (x/y) rleq: x ≤ y rabs: |x| rsub: y int-to-real: r(n) real: nat_plus: + all: x:A. B[x] and: P ∧ Q member: t ∈ T set: {x:A| B[x]}  natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T top: Top approx-in-interval: approx-in-interval(l;u;x;n) has-value: (a)↓ uall: [x:A]. B[x] uimplies: supposing a real: nat_plus: + decidable: Dec(P) or: P ∨ Q not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False and: P ∧ Q prop: bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) less_than: a < b less_than': less_than'(a;b) true: True squash: T cand: c∧ B sq_stable: SqStable(P) rneq: x ≠ y guard: {T} iff: ⇐⇒ Q rev_implies:  Q bfalse: ff sq_type: SQType(T) bnot: ¬bb ifthenelse: if then else fi  assert: b int_nzero: -o nequal: a ≠ b ∈  subtype_rel: A ⊆B rev_uimplies: rev_uimplies(P;Q) req_int_terms: t1 ≡ t2 rational-upper-approx: above within 1/n rational-approx: (x within 1/n) so_lambda: λ2x.t[x] so_apply: x[s] rless: x < y sq_exists: x:A [B[x]] rge: x ≥ y rational-lower-approx: (below within 1/n) le: A ≤ B
Lemmas referenced :  member_rccint_lemma istype-void value-type-has-value int-value-type lt_int_wf nat_plus_properties decidable__lt full-omega-unsat intformand_wf intformnot_wf intformless_wf itermConstant_wf itermMultiply_wf itermVar_wf istype-int int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_mul_lemma int_term_value_var_lemma int_formula_prop_wf istype-less_than eqtt_to_assert assert_of_lt_int istype-top rleq_weakening_equal sq_stable__rleq rleq_wf rabs_wf rsub_wf rdiv_wf int-to-real_wf rless-int rless_wf eqff_to_assert bool_cases_sqequal subtype_base_sq bool_wf bool_subtype_base assert-bnot iff_weakening_uiff assert_wf less_than_wf subtract_wf int-rdiv_wf intformeq_wf int_formula_prop_eq_lemma int_subtype_base nequal_wf nat_plus_wf i-member_wf rccint_wf real_wf radd-preserves-rleq radd_wf itermSubtract_wf itermAdd_wf rleq_functionality rabs-of-nonneg req_weakening req-iff-rsub-is-0 real_polynomial_null real_term_value_sub_lemma real_term_value_add_lemma real_term_value_var_lemma real_term_value_const_lemma set-value-type mul_preserves_lt set_subtype_base rless_functionality nat_plus_inc_int_nzero int-rdiv-req rless-int-fractions add-is-int-iff multiply-is-int-iff int_term_value_add_lemma false_wf rational-approx-property rational-upper-approx-property rational-upper-approx_wf rational-approx_wf rabs-difference-bound-rleq rleq_functionality_wrt_implies rsub_functionality_wrt_rleq req-int-fractions decidable__equal_int req_functionality req_transitivity radd-rdiv rdiv_functionality radd-int rleq_weakening_rless radd_functionality_wrt_rleq rabs-difference-symmetry subtract-is-int-iff int_term_value_subtract_lemma rational-lower-approx-property rational-lower-approx_wf rleq_transitivity decidable__le intformle_wf int_formula_prop_le_lemma mul_preserves_le nat_plus_subtype_nat rleq-int-fractions
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut sqequalRule introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin isect_memberEquality_alt voidElimination hypothesis callbyvalueReduce isectElimination intEquality independent_isectElimination applyEquality setElimination rename hypothesisEquality because_Cache multiplyEquality natural_numberEquality addEquality dependent_set_memberEquality_alt unionElimination approximateComputation independent_functionElimination dependent_pairFormation_alt lambdaEquality_alt int_eqEquality independent_pairFormation universeIsType inhabitedIsType equalityElimination equalityTransitivity equalitySymmetry productElimination lessCases isect_memberFormation_alt axiomSqEquality isectIsTypeImplies imageMemberEquality baseClosed imageElimination productIsType closedConclusion inrFormation_alt equalityIstype promote_hyp instantiate cumulativity baseApply sqequalBase setIsType applyLambdaEquality pointwiseFunctionality

Latex:
\mforall{}l:\mBbbR{}.  \mforall{}u:\{u:\mBbbR{}|  l  \mleq{}  u\}  .  \mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  [l,  u]\}  .  \mforall{}n:\mBbbN{}\msupplus{}.
    (approx-in-interval(l;u;x;n)  \mmember{}  \{y:\mBbbR{}|  (y  \mmember{}  [l,  u])  \mwedge{}  (|x  -  y|  \mleq{}  (r(2)/r(n)))\}  )



Date html generated: 2019_10_30-AM-09_07_32
Last ObjectModification: 2019_10_10-PM-01_11_54

Theory : reals


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