Nuprl Lemma : permutation-when-no_repeats
∀[T:Type]
  ∀sa,sb:T List.  ((∀x:T. ((x ∈ sa) 
⇐⇒ (x ∈ sb))) 
⇒ no_repeats(T;sb) 
⇒ no_repeats(T;sa) 
⇒ permutation(T;sb;sa))
Proof
Definitions occuring in Statement : 
permutation: permutation(T;L1;L2)
, 
no_repeats: no_repeats(T;l)
, 
l_member: (x ∈ l)
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
int_seg: {i..j-}
, 
uimplies: b supposing a
, 
lelt: i ≤ j < k
, 
and: P ∧ Q
, 
le: A ≤ B
, 
less_than: a < b
, 
squash: ↓T
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
prop: ℙ
, 
l_member: (x ∈ l)
, 
cand: A c∧ B
, 
nat: ℕ
, 
ge: i ≥ j 
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
pi1: fst(t)
, 
inject: Inj(A;B;f)
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
no_repeats: no_repeats(T;l)
, 
less_than': less_than'(a;b)
, 
sq_type: SQType(T)
, 
true: True
, 
permutation: permutation(T;L1;L2)
Lemmas referenced : 
select_wf, 
int_seg_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
istype-int, 
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, 
length_wf, 
intformless_wf, 
int_formula_prop_less_lemma, 
select_member, 
nat_properties, 
istype-le, 
istype-less_than, 
int_seg_wf, 
no_repeats_wf, 
l_member_wf, 
list_wf, 
istype-universe, 
non_neg_length, 
length_wf_nat, 
pigeon-hole, 
decidable__equal_int_seg, 
set_subtype_base, 
lelt_wf, 
int_subtype_base, 
int_seg_subtype_nat, 
istype-false, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
subtype_base_sq, 
istype-nat, 
equal_wf, 
squash_wf, 
true_wf, 
subtype_rel_self, 
iff_weakening_equal, 
le_wf, 
less_than_wf, 
decidable__equal_int, 
subtype_rel_function, 
int_seg_subtype, 
le_weakening, 
inject_wf, 
permute_list_wf, 
list_extensionality, 
permute_list_length, 
permute_list_select
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
cut, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
setElimination, 
rename, 
because_Cache, 
independent_isectElimination, 
productElimination, 
imageElimination, 
sqequalRule, 
natural_numberEquality, 
unionElimination, 
approximateComputation, 
independent_functionElimination, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
int_eqEquality, 
Error :memTop, 
independent_pairFormation, 
universeIsType, 
voidElimination, 
dependent_set_memberEquality_alt, 
productIsType, 
equalityIstype, 
functionIsType, 
inhabitedIsType, 
instantiate, 
universeEquality, 
promote_hyp, 
applyEquality, 
equalityTransitivity, 
equalitySymmetry, 
applyLambdaEquality, 
functionExtensionality, 
intEquality, 
sqequalBase, 
cumulativity, 
imageMemberEquality, 
baseClosed, 
productEquality
Latex:
\mforall{}[T:Type]
    \mforall{}sa,sb:T  List.
        ((\mforall{}x:T.  ((x  \mmember{}  sa)  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  sb)))
        {}\mRightarrow{}  no\_repeats(T;sb)
        {}\mRightarrow{}  no\_repeats(T;sa)
        {}\mRightarrow{}  permutation(T;sb;sa))
Date html generated:
2020_05_19-PM-09_45_17
Last ObjectModification:
2019_12_31-PM-00_12_11
Theory : list_1
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