Nuprl Lemma : near-inverse-of-increasing-function
∀f:ℝ ⟶ ℝ. ∀n,M:ℕ+. ∀z:ℝ. ∀a,b:ℤ.
  ∀k:ℕ+
    (∃c:ℤ. (∃j:ℕ+ [((|f[(r(c))/j] - z| ≤ (r1/r(n))) ∧ ((r(a))/k ≤ (r(c))/j) ∧ ((r(c))/j ≤ (r(b))/k))])) supposing 
       ((z ≤ f[(r(b))/k]) and 
       (f[(r(a))/k] ≤ z) and 
       (∀x,y:ℝ.
          (((r(a))/k ≤ x)
          
⇒ (x < y)
          
⇒ (y ≤ (r(b))/k)
          
⇒ ((f[x] ≤ f[y]) ∧ (((y - x) ≤ (r1/r(M))) 
⇒ ((f[y] - f[x]) ≤ (r1/r(n)))))))) 
  supposing a < b
Proof
Definitions occuring in Statement : 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rabs: |x|
, 
int-rdiv: (a)/k1
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat_plus: ℕ+
, 
less_than: a < b
, 
uimplies: b supposing a
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
uimplies: b supposing a
, 
prop: ℙ
, 
nat_plus: ℕ+
, 
nat: ℕ
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
and: P ∧ Q
, 
so_apply: x[s]
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
rless: x < y
, 
sq_exists: ∃x:A [B[x]]
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
le: A ≤ B
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
less_than: a < b
, 
squash: ↓T
, 
rdiv: (x/y)
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
true: True
, 
rev_uimplies: rev_uimplies(P;Q)
, 
cand: A c∧ B
, 
rge: x ≥ y
, 
int_nzero: ℤ-o
, 
nequal: a ≠ b ∈ T 
, 
sq_type: SQType(T)
, 
real: ℝ
, 
sq_stable: SqStable(P)
Lemmas referenced : 
real_wf, 
nat_plus_wf, 
uniform-comp-nat-induction, 
all_wf, 
isect_wf, 
less_than_wf, 
le_wf, 
subtract_wf, 
rleq_wf, 
int-rdiv_wf, 
nat_plus_inc_int_nzero, 
int-to-real_wf, 
rless_wf, 
rsub_wf, 
rdiv_wf, 
rless-int, 
nat_plus_properties, 
nat_properties, 
decidable__lt, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_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_var_lemma, 
int_formula_prop_wf, 
exists_wf, 
sq_exists_wf, 
rabs_wf, 
istype-le, 
istype-less_than, 
istype-nat, 
member-less_than, 
le_witness_for_triv, 
decidable__le, 
int_seg_wf, 
int_seg_properties, 
itermMultiply_wf, 
itermSubtract_wf, 
rinv_wf2, 
rmul_wf, 
rmul_preserves_rless, 
rleq_weakening_equal, 
rless_functionality, 
int-rdiv-req, 
req_transitivity, 
rmul_functionality, 
req_weakening, 
rmul-rinv, 
req-iff-rsub-is-0, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
int_term_value_subtract_lemma, 
int_term_value_minus_lemma, 
int_term_value_add_lemma, 
int_term_value_mul_lemma, 
int_formula_prop_le_lemma, 
intformle_wf, 
rleq-int-fractions2, 
itermMinus_wf, 
itermAdd_wf, 
rminus_wf, 
radd_wf, 
rmul_preserves_rleq, 
rleq_functionality, 
rsub_functionality, 
radd_functionality, 
rminus_functionality, 
squash_wf, 
true_wf, 
rminus-int, 
radd-int, 
rinv-mul-as-rdiv, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
rleq-implies-rleq, 
rleq_functionality_wrt_implies, 
rabs-of-nonneg, 
radd-preserves-rleq, 
mul_preserves_lt, 
rleq-int-fractions, 
set-value-type, 
equal_wf, 
int-value-type, 
nearby-cases, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
int_subtype_base, 
nequal_wf, 
rleq_weakening_rless, 
subtype_base_sq, 
decidable__equal_int, 
sq_stable__less_than, 
mul_preserves_le, 
nat_plus_subtype_nat, 
int-rdiv-cancel, 
subtype_rel_self, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
universeIsType, 
introduction, 
extract_by_obid, 
hypothesis, 
because_Cache, 
functionIsType, 
inhabitedIsType, 
hypothesisEquality, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
sqequalRule, 
lambdaEquality_alt, 
closedConclusion, 
intEquality, 
multiplyEquality, 
setElimination, 
rename, 
functionEquality, 
applyEquality, 
productEquality, 
natural_numberEquality, 
independent_isectElimination, 
inrFormation_alt, 
dependent_functionElimination, 
productElimination, 
independent_functionElimination, 
unionElimination, 
approximateComputation, 
dependent_pairFormation_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
independent_pairFormation, 
productIsType, 
isect_memberFormation_alt, 
equalityTransitivity, 
equalitySymmetry, 
independent_pairEquality, 
functionIsTypeImplies, 
isectIsType, 
imageElimination, 
setIsType, 
minusEquality, 
addEquality, 
imageMemberEquality, 
baseClosed, 
dependent_set_memberFormation_alt, 
cutEval, 
dependent_set_memberEquality_alt, 
equalityIstype, 
sqequalBase, 
instantiate, 
cumulativity, 
promote_hyp, 
baseApply, 
universeEquality
Latex:
\mforall{}f:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}n,M:\mBbbN{}\msupplus{}.  \mforall{}z:\mBbbR{}.  \mforall{}a,b:\mBbbZ{}.
    \mforall{}k:\mBbbN{}\msupplus{}
        (\mexists{}c:\mBbbZ{}
            (\mexists{}j:\mBbbN{}\msupplus{}  [((|f[(r(c))/j]  -  z|  \mleq{}  (r1/r(n)))
                          \mwedge{}  ((r(a))/k  \mleq{}  (r(c))/j)
                          \mwedge{}  ((r(c))/j  \mleq{}  (r(b))/k))]))  supposing 
              ((z  \mleq{}  f[(r(b))/k])  and 
              (f[(r(a))/k]  \mleq{}  z)  and 
              (\mforall{}x,y:\mBbbR{}.
                    (((r(a))/k  \mleq{}  x)
                    {}\mRightarrow{}  (x  <  y)
                    {}\mRightarrow{}  (y  \mleq{}  (r(b))/k)
                    {}\mRightarrow{}  ((f[x]  \mleq{}  f[y])  \mwedge{}  (((y  -  x)  \mleq{}  (r1/r(M)))  {}\mRightarrow{}  ((f[y]  -  f[x])  \mleq{}  (r1/r(n)))))))) 
    supposing  a  <  b
Date html generated:
2019_10_29-AM-10_06_47
Last ObjectModification:
2019_10_10-AM-10_23_54
Theory : reals
Home
Index