Nuprl Lemma : sorted-filter
∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[L:T List].  sorted(filter(P;L)) supposing sorted(L) supposing T ⊆r ℤ
Proof
Definitions occuring in Statement : 
sorted: sorted(L)
, 
filter: filter(P;l)
, 
list: T List
, 
bool: 𝔹
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
function: x:A ⟶ B[x]
, 
int: ℤ
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
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
, 
sorted: sorted(L)
, 
le: A ≤ B
, 
and: P ∧ Q
, 
not: ¬A
, 
false: False
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
cand: A c∧ B
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
list_induction, 
sorted_wf, 
filter_wf5, 
subtype_rel_dep_function, 
bool_wf, 
l_member_wf, 
subtype_rel_self, 
set_wf, 
list_wf, 
filter_nil_lemma, 
filter_cons_lemma, 
nil_wf, 
sorted-cons, 
cons_wf, 
equal-wf-T-base, 
assert_wf, 
bnot_wf, 
not_wf, 
eqtt_to_assert, 
uiff_transitivity, 
eqff_to_assert, 
assert_of_bnot, 
equal_wf, 
l_all_iff, 
le_wf, 
member_filter
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
cumulativity, 
independent_isectElimination, 
hypothesis, 
applyEquality, 
because_Cache, 
setEquality, 
setElimination, 
rename, 
lambdaFormation, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
independent_pairEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
functionExtensionality, 
independent_pairFormation, 
baseClosed, 
unionElimination, 
equalityElimination
Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].    sorted(filter(P;L))  supposing  sorted(L)  supposing  T  \msubseteq{}r  \mBbbZ{}
Date html generated:
2017_04_14-AM-08_52_48
Last ObjectModification:
2017_02_27-PM-03_38_25
Theory : list_0
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