Nuprl Lemma : not-l_exists
∀[T:Type]. ∀L:T List. ∀[P:{x:T| (x ∈ L)}  ⟶ ℙ]. (¬(∃x∈L. P[x]) ⇐⇒ (∀x∈L.¬P[x]))
Proof
Definitions occuring in Statement : 
l_exists: (∃x∈L. P[x]), 
l_all: (∀x∈L.P[x]), 
l_member: (x ∈ l), 
list: T List, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s], 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
not: ¬A, 
set: {x:A| B[x]} , 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
not: ¬A, 
false: False, 
member: t ∈ T, 
prop: ℙ, 
so_apply: x[s], 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x.t[x], 
subtype_rel: A ⊆r B, 
rev_implies: P ⇐ Q, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
exists: ∃x:A. B[x], 
guard: {T}, 
int_seg: {i..j-}, 
sq_stable: SqStable(P), 
lelt: i ≤ j < k, 
squash: ↓T, 
l_all: (∀x∈L.P[x]), 
cand: A c∧ B
Lemmas referenced : 
list_wf, 
length_wf, 
int_seg_wf, 
sq_stable__le, 
list-subtype, 
select_wf, 
l_all_wf, 
l_exists_wf, 
l_all_iff, 
l_exists_iff, 
iff_wf, 
exists_wf, 
not_over_exists, 
not_wf, 
all_wf, 
l_member_wf
Rules used in proof : 
cut, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
independent_pairFormation, 
lambdaFormation, 
thin, 
because_Cache, 
hypothesis, 
sqequalHypSubstitution, 
independent_functionElimination, 
voidElimination, 
applyEquality, 
hypothesisEquality, 
dependent_set_memberEquality, 
lemma_by_obid, 
isectElimination, 
cumulativity, 
sqequalRule, 
lambdaEquality, 
productEquality, 
productElimination, 
functionEquality, 
addLevel, 
impliesFunctionality, 
independent_isectElimination, 
universeEquality, 
dependent_functionElimination, 
setEquality, 
impliesLevelFunctionality, 
equalityTransitivity, 
equalitySymmetry, 
setElimination, 
rename, 
natural_numberEquality, 
introduction, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
isect_memberFormation, 
independent_pairEquality, 
isect_memberEquality
Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}[P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbP{}].  (\mneg{}(\mexists{}x\mmember{}L.  P[x])  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}x\mmember{}L.\mneg{}P[x]))
Date html generated:
2016_05_14-AM-06_40_52
Last ObjectModification:
2016_01_14-PM-08_20_13
Theory : list_0
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