Nuprl Lemma : dec-exists-int-seg
∀a,b:ℤ.  ∀[F:{a..b-} ⟶ ℙ]. ((∀k:{a..b-}. Dec(F[k])) ⇒ Dec(∃k:{a..b-}. F[k]))
Proof
Definitions occuring in Statement : 
int_seg: {i..j-}, 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
implies: P ⇒ Q, 
function: x:A ⟶ B[x], 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
prop: ℙ
Lemmas referenced : 
decidable_wf, 
all_wf, 
int_seg_wf, 
decidable__exists_int_seg
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
cut, 
thin, 
instantiate, 
lemma_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
isectElimination, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
hypothesis, 
independent_functionElimination, 
functionEquality, 
cumulativity, 
universeEquality, 
intEquality
Latex:
\mforall{}a,b:\mBbbZ{}.    \mforall{}[F:\{a..b\msupminus{}\}  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}k:\{a..b\msupminus{}\}.  Dec(F[k]))  {}\mRightarrow{}  Dec(\mexists{}k:\{a..b\msupminus{}\}.  F[k]))
Date html generated:
2016_05_14-PM-09_56_16
Last ObjectModification:
2016_01_16-PM-05_37_41
Theory : continuity
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