Nuprl Lemma : ddr_wf
∀x:ℝ. ∀n:ℕ+.  (ddr(x;n) ∈ {y:ℝ| |x - y| ≤ (r1/r(5 * 10^n - 1))} )
Proof
Definitions occuring in Statement : 
ddr: ddr(x;n)
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rabs: |x|
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
exp: i^n
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
, 
multiply: n * m
, 
subtract: n - m
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
nat: ℕ
, 
nat_plus: ℕ+
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
ddr: ddr(x;n)
, 
subtype_rel: A ⊆r B
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
true: True
, 
guard: {T}
, 
le: A ≤ B
, 
int_upper: {i...}
, 
has-value: (a)↓
, 
int_nzero: ℤ-o
, 
nequal: a ≠ b ∈ T 
, 
sq_type: SQType(T)
, 
uiff: uiff(P;Q)
, 
real: ℝ
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
ge: i ≥ j 
, 
subtract: n - m
, 
rneq: x ≠ y
, 
rev_uimplies: rev_uimplies(P;Q)
, 
rge: x ≥ y
, 
rational-approx: (x within 1/n)
, 
divides: b | a
Lemmas referenced : 
rational-approx-property, 
mul_nat_plus, 
exp_wf_nat_plus, 
subtract_wf, 
nat_plus_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermSubtract_wf, 
itermVar_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_subtract_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
le_wf, 
nat_plus_wf, 
real_wf, 
exp-fastexp, 
nat_plus_subtype_nat, 
exp_wf2, 
less_than_wf, 
mul_preserves_le, 
false_wf, 
exp_step, 
itermMultiply_wf, 
int_term_value_mul_lemma, 
int_upper_wf, 
int_upper_properties, 
value-type-has-value, 
int-value-type, 
div_rem_sum, 
subtype_base_sq, 
int_subtype_base, 
equal-wf-base, 
true_wf, 
nequal_wf, 
rem_bounds_1, 
int_upper_subtype_nat, 
add-is-int-iff, 
multiply-is-int-iff, 
intformeq_wf, 
itermAdd_wf, 
int_formula_prop_eq_lemma, 
int_term_value_add_lemma, 
decidable__lt, 
not-lt-2, 
add_functionality_wrt_le, 
add-commutes, 
zero-add, 
le-add-cancel, 
rat-to-real_wf, 
subtype_rel_sets, 
equal_wf, 
rleq_wf, 
rabs_wf, 
rsub_wf, 
rdiv_wf, 
int-to-real_wf, 
rneq-int, 
int_entire_a, 
set_subtype_base, 
exp_wf4, 
nat_wf, 
div-cancel2, 
nat_properties, 
decidable__equal_int, 
rational-approx_wf, 
le_antisymmetry_iff, 
condition-implies-le, 
minus-one-mul, 
minus-one-mul-top, 
mul-associates, 
add-associates, 
add-swap, 
rless-int, 
rless_wf, 
rleq_functionality_wrt_implies, 
rleq_weakening_equal, 
div_rem_sum2, 
divides_iff_rem_zero, 
equal-wf-T-base, 
rat-to-real-req, 
int-rdiv_wf, 
rleq_functionality, 
req_weakening, 
rabs_functionality, 
rsub_functionality, 
int-rdiv-req
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
isectElimination, 
because_Cache, 
dependent_set_memberEquality, 
setElimination, 
rename, 
hypothesis, 
natural_numberEquality, 
unionElimination, 
independent_isectElimination, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
sqequalRule, 
independent_pairFormation, 
computeAll, 
applyEquality, 
imageMemberEquality, 
baseClosed, 
equalityTransitivity, 
equalitySymmetry, 
applyLambdaEquality, 
productElimination, 
callbyvalueReduce, 
addLevel, 
instantiate, 
cumulativity, 
independent_functionElimination, 
divideEquality, 
imageElimination, 
pointwiseFunctionality, 
promote_hyp, 
baseApply, 
closedConclusion, 
setEquality, 
multiplyEquality, 
addEquality, 
minusEquality, 
inrFormation
Latex:
\mforall{}x:\mBbbR{}.  \mforall{}n:\mBbbN{}\msupplus{}.    (ddr(x;n)  \mmember{}  \{y:\mBbbR{}|  |x  -  y|  \mleq{}  (r1/r(5  *  10\^{}n  -  1))\}  )
Date html generated:
2017_10_03-AM-08_45_16
Last ObjectModification:
2017_07_28-AM-07_31_58
Theory : reals
Home
Index