Nuprl Lemma : rational-lower-approx-property

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


Proof




Definitions occuring in Statement :  rational-lower-approx: (below x within 1/n),  rdiv: (x/y),  rleq: x ≤ y,  radd: a + b,  int-to-real: r(n),  real: ℝ,  nat_plus: ℕ+,  all: ∀x:A. B[x],  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  nat_plus: ℕ+,  uall: ∀[x:A]. B[x],  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  and: P ∧ Q,  prop: ℙ,  rational-approx: (x within 1/n),  rational-lower-approx: (below x within 1/n),  real: ℝ,  has-value: (a)↓,  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  subtype_rel: A ⊆r B,  rneq: x ≠ y,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  rat_term_to_real: rat_term_to_real(f;t),  rtermSubtract: left "-" right,  rat_term_ind: rat_term_ind,  rtermDivide: num "/" denom,  rtermConstant: "const",  rtermVar: rtermVar(var),  pi1: fst(t),  true: True,  pi2: snd(t),  cand: A c∧ B,  rge: x ≥ y,  req_int_terms: t1 ≡ t2
Lemmas referenced :  rational-approx-property,  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,  istype-void,  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,  nat_plus_wf,  real_wf,  value-type-has-value,  int-value-type,  subtract_wf,  int-rdiv_wf,  intformeq_wf,  int_formula_prop_eq_lemma,  int_subtype_base,  nequal_wf,  int-to-real_wf,  rsub_wf,  rdiv_wf,  rless-int,  rless_wf,  req_functionality,  int-rdiv_functionality,  req_inversion,  rsub-int,  req_weakening,  int-rdiv-req,  rsub_functionality,  req-int-fractions,  nat_plus_inc_int_nzero,  decidable__equal_int,  assert-rat-term-eq2,  rtermDivide_wf,  rtermSubtract_wf,  rtermVar_wf,  rtermConstant_wf,  rleq_wf,  radd_wf,  rabs_wf,  iff_weakening_uiff,  rleq_functionality,  radd_functionality,  rabs-difference-bound-rleq,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  itermAdd_wf,  int_term_value_add_lemma,  req_transitivity,  radd-rdiv,  rdiv_functionality,  radd-int,  req_wf,  rleq_weakening,  itermSubtract_wf,  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
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  dependent_set_memberEquality_alt,  multiplyEquality,  natural_numberEquality,  setElimination,  rename,  hypothesis,  isectElimination,  unionElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  universeIsType,  intEquality,  applyEquality,  because_Cache,  inhabitedIsType,  equalityIstype,  equalityTransitivity,  equalitySymmetry,  callbyvalueReduce,  baseApply,  closedConclusion,  baseClosed,  sqequalBase,  inrFormation_alt,  productElimination,  applyLambdaEquality,  promote_hyp,  addEquality

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



Date html generated: 2019_10_29-AM-10_01_11
Last ObjectModification: 2019_04_02-AM-10_01_41

Theory : reals


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