Nuprl Lemma : sp-lub-is-top1
∀[A:ℕ ⟶ Sierpinski]. (lub(n.A[n]) = ⊤ ∈ Sierpinski 
⇐⇒ ¬(∀n:ℕ. (A[n] = ⊥ ∈ Sierpinski)))
Proof
Definitions occuring in Statement : 
sp-lub: lub(n.A[n])
, 
Sierpinski: Sierpinski
, 
Sierpinski-top: ⊤
, 
Sierpinski-bottom: ⊥
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
not: ¬A
, 
function: x:A ⟶ B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
all_wf, 
nat_wf, 
equal-wf-T-base, 
Sierpinski_wf, 
sp-lub_wf, 
not_wf, 
Sierpinski-unequal, 
sp-lub-is-bottom, 
not-Sierpinski-bottom
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
lambdaFormation, 
thin, 
hypothesis, 
sqequalHypSubstitution, 
independent_functionElimination, 
voidElimination, 
extract_by_obid, 
isectElimination, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
hypothesisEquality, 
baseClosed, 
because_Cache, 
productElimination, 
independent_pairEquality, 
dependent_functionElimination, 
axiomEquality, 
functionEquality, 
equalitySymmetry, 
equalityTransitivity, 
promote_hyp, 
addLevel, 
impliesFunctionality, 
levelHypothesis
Latex:
\mforall{}[A:\mBbbN{}  {}\mrightarrow{}  Sierpinski].  (lub(n.A[n])  =  \mtop{}  \mLeftarrow{}{}\mRightarrow{}  \mneg{}(\mforall{}n:\mBbbN{}.  (A[n]  =  \mbot{})))
Date html generated:
2019_10_31-AM-06_36_18
Last ObjectModification:
2017_07_28-AM-09_12_09
Theory : synthetic!topology
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