Nuprl Lemma : rational-approx-property
∀x:ℝ. ∀n:ℕ+.  (|x - (x within 1/n)| ≤ (r1/r(n)))
Proof
Definitions occuring in Statement : 
rational-approx: (x within 1/n)
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rabs: |x|
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
rational-approx: (x within 1/n)
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
int_nzero: ℤ-o
, 
nat_plus: ℕ+
, 
nequal: a ≠ b ∈ T 
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
uimplies: b supposing a
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
real: ℝ
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
decidable: Dec(P)
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
true: True
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
rdiv: (x/y)
, 
itermConstant: "const"
, 
req_int_terms: t1 ≡ t2
, 
nat: ℕ
Lemmas referenced : 
nat_plus_wf, 
real_wf, 
rabs_wf, 
rsub_wf, 
int-rdiv_wf, 
nat_plus_properties, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformeq_wf, 
itermMultiply_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_mul_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
equal-wf-base, 
int_subtype_base, 
nequal_wf, 
int-to-real_wf, 
rdiv_wf, 
rless-int, 
decidable__lt, 
intformnot_wf, 
int_formula_prop_not_lemma, 
rless_wf, 
rmul_preserves_rleq, 
rmul_wf, 
radd_wf, 
rinv_wf2, 
rminus_wf, 
rleq_functionality, 
rabs_functionality, 
rsub_functionality, 
req_weakening, 
int-rdiv-req, 
req_transitivity, 
real_term_polynomial, 
itermSubtract_wf, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
req-iff-rsub-is-0, 
rmul_functionality, 
itermAdd_wf, 
itermMinus_wf, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
radd_functionality, 
rminus-rdiv, 
squash_wf, 
true_wf, 
rneq_wf, 
rminus-int, 
rmul-rinv, 
rmul-int, 
rmul-assoc, 
req_wf, 
rabs-int, 
iff_weakening_equal, 
req-int, 
absval_wf, 
nat_wf, 
equal_wf, 
absval_pos, 
decidable__le, 
intformle_wf, 
int_formula_prop_le_lemma, 
le_wf, 
req_inversion, 
rabs-rmul, 
real-approx
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality, 
multiplyEquality, 
natural_numberEquality, 
setElimination, 
rename, 
independent_isectElimination, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
sqequalRule, 
independent_pairFormation, 
computeAll, 
baseApply, 
closedConclusion, 
baseClosed, 
applyEquality, 
because_Cache, 
inrFormation, 
productElimination, 
independent_functionElimination, 
unionElimination, 
minusEquality, 
imageMemberEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality
Latex:
\mforall{}x:\mBbbR{}.  \mforall{}n:\mBbbN{}\msupplus{}.    (|x  -  (x  within  1/n)|  \mleq{}  (r1/r(n)))
Date html generated:
2017_10_03-AM-08_40_44
Last ObjectModification:
2017_07_28-AM-07_31_25
Theory : reals
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