Nuprl Lemma : member_map_filter
∀[T:Type]
  ∀P:T ⟶ 𝔹
    ∀[T':Type]
      ∀f:{x:T| ↑(P x)}  ⟶ T'. ∀L:T List. ∀x:T'.
        ((x ∈ mapfilter(f;P;L)) 
⇐⇒ ∃y:T. ((y ∈ L) ∧ ((↑(P y)) c∧ (x = (f y) ∈ T'))))
Proof
Definitions occuring in Statement : 
mapfilter: mapfilter(f;P;L)
, 
l_member: (x ∈ l)
, 
list: T List
, 
assert: ↑b
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
cand: A c∧ B
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
mapfilter: mapfilter(f;P;L)
, 
member: t ∈ T
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
, 
l_member: (x ∈ l)
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
nat: ℕ
, 
uimplies: b supposing a
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
not: ¬A
, 
top: Top
, 
sq_type: SQType(T)
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
true: True
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
filter_type, 
list_wf, 
assert_wf, 
l_member_wf, 
equal_wf, 
less_than_wf, 
length_wf, 
subtype_rel_list, 
select_wf, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
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, 
member_filter, 
assert_elim, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
exists_wf, 
l_member_set2, 
member-map, 
map_wf, 
iff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
functionExtensionality, 
applyEquality, 
hypothesis, 
setEquality, 
independent_pairFormation, 
productElimination, 
dependent_pairFormation, 
because_Cache, 
equalityElimination, 
promote_hyp, 
equalitySymmetry, 
hyp_replacement, 
applyLambdaEquality, 
setElimination, 
rename, 
dependent_set_memberEquality, 
equalityTransitivity, 
lambdaEquality, 
sqequalRule, 
productEquality, 
independent_isectElimination, 
dependent_functionElimination, 
natural_numberEquality, 
unionElimination, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
independent_functionElimination, 
addLevel, 
levelHypothesis, 
instantiate, 
impliesFunctionality, 
functionEquality, 
universeEquality
Latex:
\mforall{}[T:Type]
    \mforall{}P:T  {}\mrightarrow{}  \mBbbB{}
        \mforall{}[T':Type]
            \mforall{}f:\{x:T|  \muparrow{}(P  x)\}    {}\mrightarrow{}  T'.  \mforall{}L:T  List.  \mforall{}x:T'.
                ((x  \mmember{}  mapfilter(f;P;L))  \mLeftarrow{}{}\mRightarrow{}  \mexists{}y:T.  ((y  \mmember{}  L)  \mwedge{}  ((\muparrow{}(P  y))  c\mwedge{}  (x  =  (f  y)))))
Date html generated:
2017_04_17-AM-07_25_40
Last ObjectModification:
2017_02_27-PM-04_04_25
Theory : list_1
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