Nuprl Lemma : regular-less-iff
∀[x,y:ℝ].  (∃n:{ℕ+| (x n) + 4 < y n} ⇐⇒ ∀b:{4...}. ∃n:ℕ+. ∀m:{n...}. (x m) + b < y m)
Proof
Definitions occuring in Statement : 
real: ℝ, 
int_upper: {i...}, 
nat_plus: ℕ+, 
less_than: a < b, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
sq_exists: ∃x:{A| B[x]}, 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
apply: f a, 
add: n + m, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
member: t ∈ T, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
real: ℝ, 
so_apply: x[s], 
rev_implies: P ⇐ Q, 
nat_plus: ℕ+, 
int_upper: {i...}, 
le: A ≤ B, 
guard: {T}, 
uimplies: b supposing a, 
sq_exists: ∃x:{A| B[x]}, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
false: False, 
not: ¬A, 
top: Top, 
subtype_rel: A ⊆r B, 
uiff: uiff(P;Q), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
less_than: a < b, 
less_than': less_than'(a;b), 
true: True, 
squash: ↓T, 
bfalse: ff, 
sq_type: SQType(T), 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
nat: ℕ, 
ge: i ≥ j 
Lemmas referenced : 
int_upper_wf, 
sq_exists_wf, 
nat_plus_wf, 
less_than_wf, 
all_wf, 
exists_wf, 
less_than_transitivity1, 
real_wf, 
sq_stable__less_than, 
int_upper_properties, 
nat_plus_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
mul_preserves_le, 
nat_plus_subtype_nat, 
decidable__lt, 
intformless_wf, 
itermMultiply_wf, 
int_formula_prop_less_lemma, 
int_term_value_mul_lemma, 
multiply-is-int-iff, 
int_subtype_base, 
regular-consistency, 
subtype_rel_sets, 
le_wf, 
absval_unfold, 
subtract_wf, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
top_wf, 
add-is-int-iff, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
false_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
itermMinus_wf, 
int_term_value_minus_lemma, 
absval_wf, 
nat_wf, 
int_upper_subtype_nat, 
le_functionality, 
multiply_functionality_wrt_le, 
le_weakening, 
add_functionality_wrt_le, 
regular-less, 
absval_ifthenelse, 
subtract-is-int-iff, 
assert_wf, 
bnot_wf, 
not_wf, 
minus-is-int-iff, 
bool_cases, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_bnot
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
independent_pairFormation, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
addEquality, 
applyEquality, 
setElimination, 
rename, 
hypothesisEquality, 
because_Cache, 
dependent_set_memberEquality, 
productElimination, 
independent_isectElimination, 
promote_hyp, 
dependent_functionElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
multiplyEquality, 
baseApply, 
closedConclusion, 
baseClosed, 
setEquality, 
applyLambdaEquality, 
minusEquality, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
lessCases, 
sqequalAxiom, 
imageMemberEquality, 
imageElimination, 
independent_functionElimination, 
pointwiseFunctionality, 
instantiate, 
cumulativity, 
impliesFunctionality, 
dependent_set_memberFormation
Latex:
\mforall{}[x,y:\mBbbR{}].    (\mexists{}n:\{\mBbbN{}\msupplus{}|  (x  n)  +  4  <  y  n\}  \mLeftarrow{}{}\mRightarrow{}  \mforall{}b:\{4...\}.  \mexists{}n:\mBbbN{}\msupplus{}.  \mforall{}m:\{n...\}.  (x  m)  +  b  <  y  m)
Date html generated:
2017_10_02-PM-07_13_52
Last ObjectModification:
2017_07_28-AM-07_20_05
Theory : reals
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