Nuprl Lemma : total-function-rational-approx
∀f:ℝ ⟶ ℝ. ∀y:ℝ.  ((∀x,y:ℝ.  ((x = y) 
⇒ (f[x] = f[y]))) 
⇒ lim n→∞.f[(y within 1/n + 1)] = f[y])
Proof
Definitions occuring in Statement : 
converges-to: lim n→∞.x[n] = y
, 
rational-approx: (x within 1/n)
, 
req: x = y
, 
real: ℝ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
so_lambda: λ2x.t[x]
, 
uall: ∀[x:A]. B[x]
, 
real: ℝ
, 
nat_plus: ℕ+
, 
nat: ℕ
, 
le: A ≤ B
, 
and: P ∧ Q
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
not: ¬A
, 
rev_implies: P 
⇐ Q
, 
false: False
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
subtract: n - m
, 
subtype_rel: A ⊆r B
, 
top: Top
, 
less_than': less_than'(a;b)
, 
true: True
, 
so_apply: x[s]
Lemmas referenced : 
total-function-limit, 
rational-approx_wf, 
decidable__lt, 
false_wf, 
not-lt-2, 
condition-implies-le, 
minus-add, 
minus-one-mul, 
zero-add, 
minus-one-mul-top, 
add-commutes, 
add_functionality_wrt_le, 
add-associates, 
add-zero, 
le-add-cancel, 
less_than_wf, 
nat_wf, 
rational-approx-converges-to, 
all_wf, 
real_wf, 
req_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
isectElimination, 
setElimination, 
rename, 
because_Cache, 
dependent_set_memberEquality, 
addEquality, 
natural_numberEquality, 
productElimination, 
unionElimination, 
independent_pairFormation, 
voidElimination, 
independent_functionElimination, 
independent_isectElimination, 
applyEquality, 
isect_memberEquality, 
voidEquality, 
intEquality, 
minusEquality, 
functionEquality, 
functionExtensionality
Latex:
\mforall{}f:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}y:\mBbbR{}.    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y])))  {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.f[(y  within  1/n  +  1)]  =  f[y])
Date html generated:
2017_10_03-AM-10_21_53
Last ObjectModification:
2017_06_30-PM-04_15_10
Theory : reals
Home
Index