Nuprl Lemma : member-permutation
∀[A:Type]. ∀as,bs:A List.  (permutation(A;as;bs) 
⇒ {∀a:A. ((a ∈ as) 
⇐⇒ (a ∈ bs))})
Proof
Definitions occuring in Statement : 
permutation: permutation(T;L1;L2)
, 
l_member: (x ∈ l)
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
, 
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
, 
guard: {T}
, 
prop: ℙ
, 
l_contains: A ⊆ B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
permutation_inversion, 
permutation-contains, 
permutation_wf, 
list_wf, 
l_all_iff, 
l_member_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_functionElimination, 
independent_functionElimination, 
hypothesis, 
because_Cache, 
universeEquality, 
sqequalRule, 
lambdaEquality, 
setElimination, 
rename, 
setEquality, 
productElimination, 
independent_pairFormation
Latex:
\mforall{}[A:Type].  \mforall{}as,bs:A  List.    (permutation(A;as;bs)  {}\mRightarrow{}  \{\mforall{}a:A.  ((a  \mmember{}  as)  \mLeftarrow{}{}\mRightarrow{}  (a  \mmember{}  bs))\})
Date html generated:
2016_05_14-PM-02_21_52
Last ObjectModification:
2015_12_26-PM-04_27_32
Theory : list_1
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