Nuprl Lemma : by-nearby-cases-ext
∀[P:ℝ ⟶ ℝ ⟶ ℙ]
  ∀n:ℕ+. ∀x:ℝ.
    ((∀y:{y:ℝ| x < y} . P[x;y])
    
⇒ (∀y:{y:ℝ| y < x} . P[x;y])
    
⇒ (∀y:{y:ℝ| |x - y| ≤ (r1/r(n))} . P[x;y])
    
⇒ (∀y:ℝ. P[x;y]))
Proof
Definitions occuring in Statement : 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rabs: |x|
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
nat_plus: ℕ+
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
member: t ∈ T
, 
by-nearby-cases, 
nearby-cases-ext, 
uall: ∀[x:A]. B[x]
, 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w])
, 
so_apply: x[s1;s2;s3;s4]
, 
so_lambda: λ2x.t[x]
, 
top: Top
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
strict4: strict4(F)
, 
and: P ∧ Q
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
has-value: (a)↓
, 
prop: ℙ
, 
guard: {T}
, 
or: P ∨ Q
, 
squash: ↓T
Lemmas referenced : 
by-nearby-cases, 
lifting-strict-callbyvalue, 
top_wf, 
equal_wf, 
has-value_wf_base, 
base_wf, 
is-exception_wf, 
lifting-strict-less, 
nearby-cases-ext
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
isectElimination, 
baseClosed, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
independent_pairFormation, 
lambdaFormation, 
callbyvalueDecide, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
unionEquality, 
unionElimination, 
sqleReflexivity, 
dependent_functionElimination, 
independent_functionElimination, 
baseApply, 
closedConclusion, 
decideExceptionCases, 
inrFormation, 
because_Cache, 
imageMemberEquality, 
imageElimination, 
exceptionSqequal, 
inlFormation
Latex:
\mforall{}[P:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}  {}\mrightarrow{}  \mBbbP{}]
    \mforall{}n:\mBbbN{}\msupplus{}.  \mforall{}x:\mBbbR{}.
        ((\mforall{}y:\{y:\mBbbR{}|  x  <  y\}  .  P[x;y])
        {}\mRightarrow{}  (\mforall{}y:\{y:\mBbbR{}|  y  <  x\}  .  P[x;y])
        {}\mRightarrow{}  (\mforall{}y:\{y:\mBbbR{}|  |x  -  y|  \mleq{}  (r1/r(n))\}  .  P[x;y])
        {}\mRightarrow{}  (\mforall{}y:\mBbbR{}.  P[x;y]))
Date html generated:
2017_10_03-AM-08_48_26
Last ObjectModification:
2017_07_28-AM-07_33_25
Theory : reals
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