Nuprl Lemma : l_member-permutation
∀[T:Type]. ∀L:T List. ∀x:T.  ((x ∈ L) ⇒ (∃L':T List. permutation(T;L;[x / L'])))
Proof
Definitions occuring in Statement : 
permutation: permutation(T;L1;L2), 
l_member: (x ∈ l), 
cons: [a / b], 
list: T List, 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
implies: P ⇒ Q, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
implies: P ⇒ Q, 
prop: ℙ, 
so_apply: x[s], 
uimplies: b supposing a, 
not: ¬A, 
false: False, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
or: P ∨ Q, 
exists: ∃x:A. B[x], 
l_member: (x ∈ l), 
cand: A c∧ B, 
append: as @ bs, 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
top: Top, 
so_apply: x[s1;s2;s3]
Lemmas referenced : 
list_induction, 
all_wf, 
l_member_wf, 
exists_wf, 
list_wf, 
permutation_wf, 
cons_wf, 
null_nil_lemma, 
btrue_wf, 
member-implies-null-eq-bfalse, 
nil_wf, 
btrue_neq_bfalse, 
cons_member, 
permutation_weakening, 
and_wf, 
equal_wf, 
append_functionality_wrt_permutation, 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
permutation_transitivity, 
permutation-rotate
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
thin, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
hypothesis, 
independent_functionElimination, 
rename, 
because_Cache, 
dependent_functionElimination, 
universeEquality, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
voidElimination, 
productElimination, 
unionElimination, 
dependent_pairFormation, 
dependent_set_memberEquality, 
independent_pairFormation, 
applyEquality, 
setElimination, 
setEquality, 
isect_memberEquality, 
voidEquality
Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}x:T.    ((x  \mmember{}  L)  {}\mRightarrow{}  (\mexists{}L':T  List.  permutation(T;L;[x  /  L'])))
Date html generated:
2016_05_14-PM-02_21_44
Last ObjectModification:
2015_12_26-PM-04_28_00
Theory : list_1
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