Nuprl Lemma : CCC-Sigma02-dns
∀K:Type. (CCCNSet(K) 
⇒ (∀P:K ⟶ K ⟶ ℙ. ((∀k,m:K.  Dec(P[k;m])) 
⇒ (¬¬(∃k:K. ∀m:K. P[k;m])) 
⇒ (∃k:K. ∀m:K. P[k;m]))))
Proof
Definitions occuring in Statement : 
ccc-nset: CCCNSet(K)
, 
decidable: Dec(P)
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s1;s2]
, 
exists: ∃x:A. B[x]
, 
false: False
, 
not: ¬A
, 
or: P ∨ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
Lemmas referenced : 
istype-universe, 
ccc-nset_wf, 
decidable_wf, 
subtype_rel_self, 
istype-void, 
CCC-omni-2
Rules used in proof : 
productElimination, 
universeEquality, 
isectElimination, 
instantiate, 
applyEquality, 
Error :universeIsType, 
Error :productIsType, 
because_Cache, 
voidElimination, 
Error :inhabitedIsType, 
Error :functionIsType, 
sqequalRule, 
unionElimination, 
independent_functionElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
sqequalHypSubstitution, 
hypothesis, 
Error :lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
extract_by_obid, 
introduction, 
cut
Latex:
\mforall{}K:Type
    (CCCNSet(K)
    {}\mRightarrow{}  (\mforall{}P:K  {}\mrightarrow{}  K  {}\mrightarrow{}  \mBbbP{}.  ((\mforall{}k,m:K.    Dec(P[k;m]))  {}\mRightarrow{}  (\mneg{}\mneg{}(\mexists{}k:K.  \mforall{}m:K.  P[k;m]))  {}\mRightarrow{}  (\mexists{}k:K.  \mforall{}m:K.  P[k;m]))))
Date html generated:
2019_06_20-PM-03_02_59
Last ObjectModification:
2019_06_14-AM-10_04_54
Theory : continuity
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