Nuprl Lemma : not-not-all-int_seg-shift
∀a,b:ℤ. ∀P:{a..b-} ⟶ ℙ.  ((∀i:{a..b-}. (¬¬P[i])) 
⇒ (¬¬(∀i:{a..b-}. P[i])))
Proof
Definitions occuring in Statement : 
int_seg: {i..j-}
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
or: P ∨ Q
, 
false: False
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
Lemmas referenced : 
not-not-all-int_seg-xmiddle, 
int_seg_wf, 
istype-void, 
subtype_rel_self, 
istype-int
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_functionElimination, 
unionElimination, 
voidElimination, 
universeIsType, 
isectElimination, 
sqequalRule, 
functionIsType, 
unionIsType, 
applyEquality, 
because_Cache, 
instantiate, 
universeEquality, 
inhabitedIsType
Latex:
\mforall{}a,b:\mBbbZ{}.  \mforall{}P:\{a..b\msupminus{}\}  {}\mrightarrow{}  \mBbbP{}.    ((\mforall{}i:\{a..b\msupminus{}\}.  (\mneg{}\mneg{}P[i]))  {}\mRightarrow{}  (\mneg{}\mneg{}(\mforall{}i:\{a..b\msupminus{}\}.  P[i])))
Date html generated:
2020_05_19-PM-09_36_12
Last ObjectModification:
2019_11_04-PM-02_02_56
Theory : int_1
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