Nuprl Lemma : remove-repeats-fun-as-filter
∀[A,B:Type]. ∀[eq:EqDecider(B)]. ∀[f:A ⟶ B]. ∀[R:A ⟶ A ⟶ 𝔹]. ∀[L:A List].
  (remove-repeats-fun(eq;f;L) ~ filter(λa.(¬b(∃x∈L.R[x;a] ∧b (eq (f x) (f a)))_b);L)) supposing 
     (sorted-by(λx,y. (↑R[x;y]);L) and 
     StAntiSym(A;x,y.↑R[x;y]) and 
     Irrefl(A;x,y.↑R[x;y]))
Proof
Definitions occuring in Statement : 
remove-repeats-fun: remove-repeats-fun(eq;f;L), 
bl-exists: (∃x∈L.P[x])_b, 
sorted-by: sorted-by(R;L), 
filter: filter(P;l), 
list: T List, 
deq: EqDecider(T), 
irrefl: Irrefl(T;x,y.E[x; y]), 
st_anti_sym: StAntiSym(T;x,y.R[x; y]), 
band: p ∧b q, 
bnot: ¬bb, 
assert: ↑b, 
bool: 𝔹, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
so_apply: x[s1;s2], 
apply: f a, 
lambda: λx.A[x], 
function: x:A ⟶ B[x], 
universe: Type, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
all: ∀x:A. B[x], 
nat: ℕ, 
implies: P ⇒ Q, 
false: False, 
ge: i ≥ j , 
uimplies: b supposing a, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
not: ¬A, 
top: Top, 
and: P ∧ Q, 
prop: ℙ, 
so_apply: x[s1;s2], 
so_lambda: λ2x y.t[x; y], 
subtype_rel: A ⊆r B, 
guard: {T}, 
or: P ∨ Q, 
remove-repeats-fun: remove-repeats-fun(eq;f;L), 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
so_apply: x[s1;s2;s3], 
cons: [a / b], 
colength: colength(L), 
decidable: Dec(P), 
nil: [], 
it: ⋅, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
sq_type: SQType(T), 
less_than: a < b, 
squash: ↓T, 
less_than': less_than'(a;b), 
iff: P ⇐⇒ Q, 
deq: EqDecider(T), 
bool: 𝔹, 
unit: Unit, 
btrue: tt, 
uiff: uiff(P;Q), 
eqof: eqof(d), 
rev_implies: P ⇐ Q, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
assert: ↑b, 
irrefl: Irrefl(T;x,y.E[x; y]), 
st_anti_sym: StAntiSym(T;x,y.R[x; y]), 
cand: A c∧ B, 
band: p ∧b q, 
label: ...$L... t
Lemmas referenced : 
nat_properties, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
ge_wf, 
less_than_wf, 
sorted-by_wf, 
assert_wf, 
l_member_wf, 
st_anti_sym_wf, 
irrefl_wf, 
equal-wf-T-base, 
nat_wf, 
colength_wf_list, 
less_than_transitivity1, 
less_than_irreflexivity, 
list-cases, 
filter_nil_lemma, 
list_ind_nil_lemma, 
sorted-by_wf_nil, 
product_subtype_list, 
spread_cons_lemma, 
intformeq_wf, 
itermAdd_wf, 
int_formula_prop_eq_lemma, 
int_term_value_add_lemma, 
decidable__le, 
intformnot_wf, 
int_formula_prop_not_lemma, 
le_wf, 
equal_wf, 
subtract_wf, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
subtype_base_sq, 
set_subtype_base, 
int_subtype_base, 
decidable__equal_int, 
filter_cons_lemma, 
list_ind_cons_lemma, 
sorted-by-cons, 
filter-filter, 
bl-exists_wf, 
cons_wf, 
band_wf, 
bool_wf, 
eqtt_to_assert, 
assert-bl-exists, 
l_exists_functionality, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_band, 
safe-assert-deq, 
set_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
bool_subtype_base, 
assert-bnot, 
l_exists_wf, 
list_wf, 
deq_wf, 
l_exists_iff, 
cons_member, 
and_wf, 
l_all_iff, 
filter-sq, 
bnot_wf, 
eqof_wf, 
not_wf, 
assert_of_bnot, 
l_exists_cons, 
l_all_fwd
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
lambdaFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
setElimination, 
rename, 
intWeakElimination, 
natural_numberEquality, 
independent_isectElimination, 
dependent_pairFormation, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
sqequalRule, 
independent_pairFormation, 
computeAll, 
independent_functionElimination, 
sqequalAxiom, 
cumulativity, 
applyEquality, 
functionExtensionality, 
setEquality, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
unionElimination, 
promote_hyp, 
hypothesis_subsumption, 
productElimination, 
applyLambdaEquality, 
dependent_set_memberEquality, 
addEquality, 
baseClosed, 
instantiate, 
imageElimination, 
equalityElimination, 
productEquality, 
functionEquality, 
universeEquality, 
hyp_replacement, 
addLevel, 
impliesFunctionality, 
levelHypothesis, 
inrFormation, 
inlFormation
Latex:
\mforall{}[A,B:Type].  \mforall{}[eq:EqDecider(B)].  \mforall{}[f:A  {}\mrightarrow{}  B].  \mforall{}[R:A  {}\mrightarrow{}  A  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:A  List].
    (remove-repeats-fun(eq;f;L)  \msim{}  filter(\mlambda{}a.(\mneg{}\msubb{}(\mexists{}x\mmember{}L.R[x;a]  \mwedge{}\msubb{}  (eq  (f  x)  (f  a)))\_b);L))  supposing 
          (sorted-by(\mlambda{}x,y.  (\muparrow{}R[x;y]);L)  and 
          StAntiSym(A;x,y.\muparrow{}R[x;y])  and 
          Irrefl(A;x,y.\muparrow{}R[x;y]))
Date html generated:
2017_04_17-AM-09_12_33
Last ObjectModification:
2017_02_27-PM-05_20_42
Theory : decidable!equality
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