Nuprl Lemma : sublist_filter
∀[T:Type]. ∀L1,L2:T List. ∀P:T ⟶ 𝔹.  (L2 ⊆ filter(P;L1) 
⇐⇒ L2 ⊆ L1 ∧ (∀x∈L2.↑(P x)))
Proof
Definitions occuring in Statement : 
sublist: L1 ⊆ L2
, 
l_all: (∀x∈L.P[x])
, 
filter: filter(P;l)
, 
list: T List
, 
assert: ↑b
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
top: Top
, 
it: ⋅
, 
nil: []
, 
list_ind: list_ind, 
reduce: reduce(f;k;as)
, 
filter: filter(P;l)
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
istype: istype(T)
, 
uimplies: b supposing a
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
l_all: (∀x∈L.P[x])
, 
int_seg: {i..j-}
, 
guard: {T}
, 
lelt: i ≤ j < k
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
true: True
, 
bool: 𝔹
, 
unit: Unit
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
less_than: a < b
, 
squash: ↓T
, 
cand: A c∧ B
, 
sq_type: SQType(T)
, 
assert: ↑b
Lemmas referenced : 
istype-universe, 
filter_cons_lemma, 
cons_wf, 
istype-void, 
filter_nil_lemma, 
nil_wf, 
assert_wf, 
l_all_wf, 
l_member_wf, 
subtype_rel_dep_function, 
filter_wf5, 
sublist_wf, 
iff_wf, 
bool_wf, 
list_wf, 
list_induction, 
l_all_nil, 
assert_witness, 
select_wf, 
length_of_nil_lemma, 
int_seg_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
int_seg_wf, 
length_wf, 
l_all_wf_nil, 
false_wf, 
cons_sublist_nil, 
true_wf, 
ifthenelse_wf, 
subtype_rel_self, 
set_wf, 
nil_sublist, 
not_wf, 
bnot_wf, 
equal-wf-T-base, 
eqtt_to_assert, 
uiff_transitivity, 
eqff_to_assert, 
assert_of_bnot, 
l_all_cons, 
or_wf, 
equal_wf, 
cons_sublist_cons, 
and_wf, 
assert_elim, 
subtype_base_sq, 
bool_subtype_base, 
istype-assert
Rules used in proof : 
universeEquality, 
instantiate, 
inhabitedIsType, 
productIsType, 
functionIsType, 
voidElimination, 
isect_memberEquality_alt, 
dependent_functionElimination, 
independent_functionElimination, 
productEquality, 
rename, 
setElimination, 
independent_isectElimination, 
setIsType, 
setEquality, 
universeIsType, 
because_Cache, 
applyEquality, 
hypothesis, 
functionEquality, 
lambdaEquality_alt, 
sqequalRule, 
hypothesisEquality, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
thin, 
cut, 
lambdaFormation_alt, 
isect_memberFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
lambdaFormation, 
independent_pairFormation, 
isect_memberEquality, 
voidEquality, 
lambdaEquality, 
functionExtensionality, 
cumulativity, 
natural_numberEquality, 
productElimination, 
unionElimination, 
approximateComputation, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
independent_pairEquality, 
promote_hyp, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
baseClosed, 
equalityElimination, 
equalityIstype, 
imageElimination, 
inlFormation, 
inrFormation, 
dependent_set_memberEquality, 
applyLambdaEquality, 
inrFormation_alt, 
hyp_replacement
Latex:
\mforall{}[T:Type].  \mforall{}L1,L2:T  List.  \mforall{}P:T  {}\mrightarrow{}  \mBbbB{}.    (L2  \msubseteq{}  filter(P;L1)  \mLeftarrow{}{}\mRightarrow{}  L2  \msubseteq{}  L1  \mwedge{}  (\mforall{}x\mmember{}L2.\muparrow{}(P  x)))
Date html generated:
2019_10_15-AM-10_22_07
Last ObjectModification:
2019_08_05-PM-02_12_08
Theory : list_1
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