Nuprl Lemma : null-filter
∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[L:T List].  uiff(↑null(filter(P;L));(∀x∈L.¬↑P[x]))
Proof
Definitions occuring in Statement : 
l_all: (∀x∈L.P[x])
, 
null: null(as)
, 
filter: filter(P;l)
, 
list: T List
, 
assert: ↑b
, 
bool: 𝔹
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
not: ¬A
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
top: Top
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
cand: A c∧ B
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
not: ¬A
, 
false: False
, 
bfalse: ff
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
exists: ∃x:A. B[x]
, 
bnot: ¬bb
, 
l_all: (∀x∈L.P[x])
, 
int_seg: {i..j-}
, 
sq_stable: SqStable(P)
, 
lelt: i ≤ j < k
, 
squash: ↓T
Lemmas referenced : 
list_induction, 
assert_wf, 
null_wf, 
filter_wf5, 
l_all_wf, 
not_wf, 
l_member_wf, 
list_wf, 
filter_nil_lemma, 
null_nil_lemma, 
l_all_nil, 
true_wf, 
filter_cons_lemma, 
l_all_cons, 
bool_cases, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
eqtt_to_assert, 
assert_elim, 
cons_wf, 
subtype_rel_dep_function, 
subtype_rel_self, 
set_wf, 
null_cons_lemma, 
bfalse_wf, 
btrue_neq_bfalse, 
eqff_to_assert, 
assert_of_bnot, 
iff_imp_equal_bool, 
equal_wf, 
bool_cases_sqequal, 
and_wf, 
ifthenelse_wf, 
false_wf, 
assert-bnot, 
null_filter, 
assert_witness, 
select_wf, 
sq_stable__le, 
int_seg_wf, 
length_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
independent_pairFormation, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
cumulativity, 
applyEquality, 
because_Cache, 
hypothesis, 
functionExtensionality, 
setElimination, 
rename, 
setEquality, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
lambdaFormation, 
productElimination, 
unionElimination, 
instantiate, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
addLevel, 
levelHypothesis, 
equalityElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_set_memberEquality, 
applyLambdaEquality, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
universeEquality, 
independent_pairEquality
Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].    uiff(\muparrow{}null(filter(P;L));(\mforall{}x\mmember{}L.\mneg{}\muparrow{}P[x]))
Date html generated:
2017_04_14-AM-08_52_28
Last ObjectModification:
2017_02_27-PM-03_38_29
Theory : list_0
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