Nuprl Lemma : function-limit
∀I:Interval. ∀f:I ⟶ℝ. ∀y:ℝ. ∀x:ℕ ⟶ ℝ.
  ((∀x,y:{x:ℝ| x ∈ I} .  ((x = y) 
⇒ (f(x) = f(y))))
  
⇒ lim n→∞.x[n] = y
  
⇒ (y ∈ I)
  
⇒ (∀n:ℕ. (x[n] ∈ I))
  
⇒ lim n→∞.f(x[n]) = f(y))
Proof
Definitions occuring in Statement : 
r-ap: f(x)
, 
rfun: I ⟶ℝ
, 
i-member: r ∈ I
, 
interval: Interval
, 
converges-to: lim n→∞.x[n] = y
, 
req: x = y
, 
real: ℝ
, 
nat: ℕ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
so_apply: x[s]
, 
prop: ℙ
, 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
rfun: I ⟶ℝ
, 
so_lambda: λ2x.t[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
Lemmas referenced : 
interval_wf, 
rfun_wf, 
nat_wf, 
req_wf, 
all_wf, 
i-member_wf, 
real_wf, 
sq_stable__i-member, 
r-ap_wf, 
function-is-continuous, 
continuous-limit
Rules used in proof : 
functionEquality, 
setEquality, 
imageElimination, 
baseClosed, 
imageMemberEquality, 
independent_isectElimination, 
because_Cache, 
rename, 
setElimination, 
isectElimination, 
lambdaEquality, 
sqequalRule, 
independent_functionElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
hypothesis, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
extract_by_obid, 
introduction, 
cut
Latex:
\mforall{}I:Interval.  \mforall{}f:I  {}\mrightarrow{}\mBbbR{}.  \mforall{}y:\mBbbR{}.  \mforall{}x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.x[n]  =  y
    {}\mRightarrow{}  (y  \mmember{}  I)
    {}\mRightarrow{}  (\mforall{}n:\mBbbN{}.  (x[n]  \mmember{}  I))
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.f(x[n])  =  f(y))
Date html generated:
2017_10_03-AM-10_19_08
Last ObjectModification:
2017_07_31-AM-11_47_30
Theory : reals
Home
Index