Nuprl Lemma : filter_iseg2
∀[T:Type]. ∀L2,L1:T List. ∀P:{x:T| (x ∈ L2)}  ⟶ 𝔹.  (L1 ≤ L2 
⇒ filter(P;L1) ≤ filter(P;L2))
Proof
Definitions occuring in Statement : 
iseg: l1 ≤ l2
, 
l_member: (x ∈ l)
, 
filter: filter(P;l)
, 
list: T List
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
istype: istype(T)
, 
top: Top
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
uiff: uiff(P;Q)
, 
rev_implies: P 
⇐ Q
, 
or: P ∨ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
ifthenelse: if b then t else f fi 
, 
cons: [a / b]
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
assert: ↑b
, 
false: False
, 
cand: A c∧ B
, 
squash: ↓T
, 
not: ¬A
Lemmas referenced : 
list_induction, 
list_wf, 
l_member_wf, 
bool_wf, 
iseg_wf, 
filter_wf5, 
subtype_rel_dep_function, 
subtype_rel_sets_simple, 
iseg_member, 
filter_nil_lemma, 
istype-void, 
nil_wf, 
filter_cons_lemma, 
cons_wf, 
istype-universe, 
iseg_nil, 
assert_of_null, 
sqequal-nil, 
nil_iseg, 
cons_member, 
eqtt_to_assert, 
list-cases, 
product_subtype_list, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
cons_iseg, 
equal_wf, 
assert_elim, 
bfalse_wf, 
bnot_wf, 
btrue_neq_bfalse, 
not_assert_elim
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
Error :lambdaFormation_alt, 
cut, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
Error :lambdaEquality_alt, 
functionEquality, 
hypothesis, 
setEquality, 
applyEquality, 
Error :setIsType, 
Error :universeIsType, 
because_Cache, 
independent_isectElimination, 
dependent_functionElimination, 
independent_functionElimination, 
Error :isect_memberEquality_alt, 
voidElimination, 
Error :functionIsType, 
rename, 
Error :inhabitedIsType, 
instantiate, 
universeEquality, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
Error :inlFormation_alt, 
Error :dependent_set_memberEquality_alt, 
unionElimination, 
equalityElimination, 
Error :inrFormation_alt, 
Error :equalityIstype, 
promote_hyp, 
hypothesis_subsumption, 
Error :dependent_pairFormation_alt, 
cumulativity, 
hyp_replacement, 
applyLambdaEquality, 
independent_pairFormation, 
setElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
Error :productIsType
Latex:
\mforall{}[T:Type].  \mforall{}L2,L1:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L2)\}    {}\mrightarrow{}  \mBbbB{}.    (L1  \mleq{}  L2  {}\mRightarrow{}  filter(P;L1)  \mleq{}  filter(P;L2))
Date html generated:
2019_06_20-PM-01_29_10
Last ObjectModification:
2019_01_17-PM-04_24_47
Theory : list_1
Home
Index