Nuprl Lemma : bdd-diff-iff-eventual
∀f,g:ℕ+ ⟶ ℤ.  (∃m:ℕ+. ∃B:ℕ. ∀n:{m...}. (|(f n) - g n| ≤ B) ⇐⇒ bdd-diff(f;g))
Proof
Definitions occuring in Statement : 
bdd-diff: bdd-diff(f;g), 
absval: |i|, 
int_upper: {i...}, 
nat_plus: ℕ+, 
nat: ℕ, 
le: A ≤ B, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
apply: f a, 
function: x:A ⟶ B[x], 
subtract: n - m, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
member: t ∈ T, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x.t[x], 
nat_plus: ℕ+, 
int_upper: {i...}, 
nat: ℕ, 
le: A ≤ B, 
guard: {T}, 
uimplies: b supposing a, 
subtype_rel: A ⊆r B, 
so_apply: x[s], 
rev_implies: P ⇐ Q, 
exists: ∃x:A. B[x], 
decidable: Dec(P), 
or: P ∨ Q, 
sq_type: SQType(T), 
bdd-diff: bdd-diff(f;g), 
ge: i ≥ j , 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
false: False, 
not: ¬A, 
top: Top, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
bnot: ¬bb, 
assert: ↑b, 
cand: A c∧ B, 
less_than': less_than'(a;b), 
true: True, 
less_than: a < b, 
squash: ↓T
Lemmas referenced : 
exists_wf, 
nat_plus_wf, 
nat_wf, 
all_wf, 
int_upper_wf, 
le_wf, 
absval_wf, 
subtract_wf, 
less_than_transitivity1, 
less_than_wf, 
bdd-diff_wf, 
decidable__equal_int, 
subtype_base_sq, 
int_subtype_base, 
subtype_rel_sets, 
nat_plus_properties, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermVar_wf, 
intformless_wf, 
itermConstant_wf, 
intformeq_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_wf, 
imax_wf, 
imax-list_wf, 
map-length, 
length-from-upto, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
decidable__lt, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
bool_subtype_base, 
assert-bnot, 
imax_ub, 
imax-list-ub, 
map_wf, 
false_wf, 
not-lt-2, 
add_functionality_wrt_le, 
add-commutes, 
zero-add, 
le-add-cancel, 
from-upto_wf, 
l_exists_iff, 
l_member_wf, 
member-map, 
member-from-upto
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
setElimination, 
rename, 
because_Cache, 
applyEquality, 
functionExtensionality, 
hypothesisEquality, 
dependent_set_memberEquality, 
productElimination, 
natural_numberEquality, 
independent_isectElimination, 
functionEquality, 
intEquality, 
dependent_functionElimination, 
unionElimination, 
instantiate, 
cumulativity, 
independent_functionElimination, 
dependent_pairFormation, 
setEquality, 
applyLambdaEquality, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
promote_hyp, 
inlFormation, 
inrFormation, 
productEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}f,g:\mBbbN{}\msupplus{}  {}\mrightarrow{}  \mBbbZ{}.    (\mexists{}m:\mBbbN{}\msupplus{}.  \mexists{}B:\mBbbN{}.  \mforall{}n:\{m...\}.  (|(f  n)  -  g  n|  \mleq{}  B)  \mLeftarrow{}{}\mRightarrow{}  bdd-diff(f;g))
Date html generated:
2017_10_02-PM-07_13_04
Last ObjectModification:
2017_07_28-AM-07_20_00
Theory : reals
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