Nuprl Lemma : l_member-permute
∀[T:Type]. ∀as,bs:T List. ∀x:T.  ((x ∈ as @ bs) 
⇐⇒ (x ∈ bs @ as))
Proof
Definitions occuring in Statement : 
l_member: (x ∈ l)
, 
append: as @ bs
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
guard: {T}
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
l_member_wf, 
or_wf, 
member_append, 
append_wf, 
iff_wf, 
list_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
independent_pairFormation, 
sqequalHypSubstitution, 
unionElimination, 
thin, 
sqequalRule, 
hypothesis, 
inrFormation, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
inlFormation, 
because_Cache, 
addLevel, 
productElimination, 
independent_functionElimination, 
dependent_functionElimination, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}as,bs:T  List.  \mforall{}x:T.    ((x  \mmember{}  as  @  bs)  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  bs  @  as))
Date html generated:
2019_10_15-AM-11_13_36
Last ObjectModification:
2018_08_25-PM-00_07_14
Theory : general
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