Nuprl Lemma : mapfilter-no-rep-fun
∀[T,U,V:Type]. ∀[eq:EqDecider(U)]. ∀[L:T List]. ∀[u:U]. ∀[f:T ⟶ U]. ∀[g:{x:{x:T| (x ∈ L)} | ↑(eq f[x] u)}  ⟶ V].
  ||mapfilter(g;λx.(eq f[x] u);L)|| ≤ 1 supposing no_repeats(U;map(f;L))
Proof
Definitions occuring in Statement : 
mapfilter: mapfilter(f;P;L)
, 
no_repeats: no_repeats(T;l)
, 
l_member: (x ∈ l)
, 
length: ||as||
, 
map: map(f;as)
, 
list: T List
, 
deq: EqDecider(T)
, 
assert: ↑b
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
le: A ≤ B
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
lambda: λx.A[x]
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
deq: EqDecider(T)
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
cand: A c∧ B
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
not: ¬A
, 
top: Top
, 
le: A ≤ B
, 
mapfilter: mapfilter(f;P;L)
, 
true: True
, 
squash: ↓T
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
eqof: eqof(d)
, 
uiff: uiff(P;Q)
, 
less_than': less_than'(a;b)
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
less_than: a < b
, 
l_before: x before y ∈ l
, 
sublist: L1 ⊆ L2
, 
select: L[n]
, 
cons: [a / b]
, 
subtract: n - m
, 
no_repeats: no_repeats(T;l)
, 
ge: i ≥ j 
, 
nat: ℕ
, 
increasing: increasing(f;k)
Lemmas referenced : 
length_wf, 
mapfilter-wf, 
subtype_rel_dep_function, 
l_member_wf, 
assert_wf, 
subtype_rel_sets, 
set_wf, 
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, 
less_than'_wf, 
no_repeats_wf, 
map_wf, 
list_wf, 
deq_wf, 
length-map, 
filter_wf5, 
filter_is_sublist, 
sublist_wf, 
equal_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
member_filter_2, 
safe-assert-deq, 
select_wf, 
false_wf, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
select_member, 
lelt_wf, 
l_before_sublist, 
l_before_select, 
le_wf, 
length_of_cons_lemma, 
length_of_nil_lemma, 
int_seg_wf, 
map-length, 
non_neg_length, 
length_wf_nat, 
nat_properties, 
int_seg_properties, 
nat_wf, 
subtype_rel_list, 
top_wf, 
select-map, 
intformeq_wf, 
int_formula_prop_eq_lemma
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
lambdaEquality, 
applyEquality, 
setElimination, 
rename, 
hypothesis, 
functionExtensionality, 
cumulativity, 
sqequalRule, 
setEquality, 
productEquality, 
independent_isectElimination, 
lambdaFormation, 
productElimination, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
natural_numberEquality, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll, 
functionEquality, 
universeEquality, 
isect_memberFormation, 
independent_pairEquality, 
axiomEquality, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
independent_functionElimination, 
dependent_set_memberEquality, 
hyp_replacement, 
applyLambdaEquality
Latex:
\mforall{}[T,U,V:Type].  \mforall{}[eq:EqDecider(U)].  \mforall{}[L:T  List].  \mforall{}[u:U].  \mforall{}[f:T  {}\mrightarrow{}  U].  \mforall{}[g:\{x:\{x:T|  (x  \mmember{}  L)\}  | 
                                                                                                                                                    \muparrow{}(eq  f[x]  u)\}    {}\mrightarrow{}  V].
    ||mapfilter(g;\mlambda{}x.(eq  f[x]  u);L)||  \mleq{}  1  supposing  no\_repeats(U;map(f;L))
Date html generated:
2017_09_29-PM-06_04_32
Last ObjectModification:
2017_07_26-PM-02_53_05
Theory : decidable!equality
Home
Index