Nuprl Lemma : dyadic-scaled-rationals-dense

a:ℝ((r0 < a)  dense-in-interval((-∞, ∞);λr.∃n:ℤ. ∃m:ℕ+(r (r(n) (a/r(2^m))))))


Proof




Definitions occuring in Statement :  dense-in-interval: dense-in-interval(I;X) riiint: (-∞, ∞) rdiv: (x/y) rless: x < y req: y rmul: b int-to-real: r(n) real: exp: i^n nat_plus: + all: x:A. B[x] exists: x:A. B[x] implies:  Q lambda: λx.A[x] natural_number: $n int:
Definitions unfolded in proof :  so_apply: x[s] so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: member: t ∈ T dense-in-interval: dense-in-interval(I;X) implies:  Q all: x:A. B[x] top: Top not: ¬A false: False req_int_terms: t1 ≡ t2 rdiv: (x/y) uiff: uiff(P;Q) rev_implies:  Q and: P ∧ Q iff: ⇐⇒ Q or: P ∨ Q guard: {T} rneq: x ≠ y uimplies: supposing a true: True exists: x:A. B[x] less_than': less_than'(a;b) squash: T less_than: a < b nat_plus: + subtype_rel: A ⊆B cand: c∧ B rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  int-to-real_wf riiint_wf i-member_wf real_wf set_wf rless_wf real_term_value_const_lemma real_term_value_var_lemma real_term_value_mul_lemma real_term_value_sub_lemma real_polynomial_null rmul-rinv3 req_transitivity rless_functionality req-iff-rsub-is-0 itermVar_wf itermMultiply_wf itermSubtract_wf rinv_wf2 rmul_wf rdiv_wf rmul_preserves_rless dyadic-rationals-dense true_wf member_riiint_lemma less_than_wf exp-positive rless-int nat_plus_subtype_nat exp_wf2 rmul_preserves_req rmul_comm rsub_wf req_wf nat_plus_wf exists_wf rless-implies-rless req_weakening req_functionality
Rules used in proof :  natural_numberEquality lambdaEquality hypothesis hypothesisEquality setElimination thin isectElimination sqequalHypSubstitution extract_by_obid introduction cut rename sqequalRule lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution voidEquality voidElimination isect_memberEquality intEquality int_eqEquality approximateComputation productElimination independent_functionElimination inrFormation independent_isectElimination because_Cache dependent_functionElimination dependent_set_memberEquality baseClosed imageMemberEquality independent_pairFormation applyEquality productEquality dependent_pairFormation

Latex:
\mforall{}a:\mBbbR{}.  ((r0  <  a)  {}\mRightarrow{}  dense-in-interval((-\minfty{},  \minfty{});\mlambda{}r.\mexists{}n:\mBbbZ{}.  \mexists{}m:\mBbbN{}\msupplus{}.  (r  =  (r(n)  *  (a/r(2\^{}m))))))



Date html generated: 2017_10_03-AM-10_21_05
Last ObjectModification: 2017_08_01-PM-02_15_13

Theory : reals


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