Nuprl Lemma : decidable__exists_int_seg
∀i,j:ℤ.  ∀[F:{i..j-} ⟶ ℙ{u}]. ((∀k:{i..j-}. Dec(F[k])) 
⇒ Dec(∃k:{i..j-}. 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
, 
has-value: (a)↓
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
Lemmas referenced : 
value-type-has-value, 
int-value-type, 
int_seg_decide_wf, 
int_seg_wf, 
all_wf, 
decidable_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
rename, 
introduction, 
sqequalRule, 
callbyvalueReduce, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
intEquality, 
independent_isectElimination, 
hypothesis, 
hypothesisEquality, 
because_Cache, 
lambdaEquality, 
applyEquality, 
instantiate, 
cumulativity, 
functionEquality, 
universeEquality
Latex:
\mforall{}i,j:\mBbbZ{}.    \mforall{}[F:\{i..j\msupminus{}\}  {}\mrightarrow{}  \mBbbP{}\{u\}].  ((\mforall{}k:\{i..j\msupminus{}\}.  Dec(F[k]))  {}\mRightarrow{}  Dec(\mexists{}k:\{i..j\msupminus{}\}.  F[k]))
Date html generated:
2016_05_13-PM-03_47_46
Last ObjectModification:
2015_12_26-AM-09_57_49
Theory : call!by!value_2
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