Nuprl Lemma : l_before_filter
∀[T:Type]. ∀l:T List. ∀P:T ⟶ 𝔹. ∀x,y:T.  (x before y ∈ filter(P;l) 
⇐⇒ (↑(P x)) ∧ (↑(P y)) ∧ x before y ∈ l)
Proof
Definitions occuring in Statement : 
l_before: x before y ∈ l
, 
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 : 
l_before: x before y ∈ l
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
, 
top: Top
, 
l_all: (∀x∈L.P[x])
, 
int_seg: {i..j-}
, 
uimplies: b supposing a
, 
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
Lemmas referenced : 
assert_witness, 
sublist_wf, 
cons_wf, 
nil_wf, 
assert_wf, 
l_all_wf_nil, 
l_all_nil, 
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_cons, 
l_all_wf, 
l_member_wf, 
sublist_filter, 
filter_wf5, 
subtype_rel_dep_function, 
bool_wf, 
subtype_rel_self, 
set_wf, 
list_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
Error :isect_memberFormation_alt, 
Error :lambdaFormation_alt, 
cut, 
independent_pairFormation, 
lambdaFormation, 
introduction, 
sqequalHypSubstitution, 
productElimination, 
thin, 
hypothesis, 
extract_by_obid, 
isectElimination, 
applyEquality, 
hypothesisEquality, 
independent_functionElimination, 
productEquality, 
lambdaEquality, 
voidElimination, 
voidEquality, 
isect_memberEquality, 
dependent_functionElimination, 
functionExtensionality, 
cumulativity, 
because_Cache, 
setElimination, 
rename, 
independent_isectElimination, 
natural_numberEquality, 
unionElimination, 
approximateComputation, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
promote_hyp, 
setEquality, 
Error :inhabitedIsType, 
Error :universeIsType, 
Error :functionIsType, 
universeEquality
Latex:
\mforall{}[T:Type]
    \mforall{}l:T  List.  \mforall{}P:T  {}\mrightarrow{}  \mBbbB{}.  \mforall{}x,y:T.    (x  before  y  \mmember{}  filter(P;l)  \mLeftarrow{}{}\mRightarrow{}  (\muparrow{}(P  x))  \mwedge{}  (\muparrow{}(P  y))  \mwedge{}  x  before  y  \mmember{}  l)
Date html generated:
2019_06_20-PM-01_25_34
Last ObjectModification:
2018_09_26-PM-05_30_39
Theory : list_1
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