Nuprl Lemma : bag-remove1-property1
∀[T:Type]
  ∀eq:EqDecider(T). ∀x:T. ∀L:T List.
    ((∃as,bs:T List. ((L = ((as @ [x]) @ bs) ∈ (T List)) ∧ (bag-remove1(eq;L;x) = (inl (rev(as) @ bs)) ∈ (T List?))))
    ∨ ((¬(x ∈ L)) ∧ (bag-remove1(eq;L;x) = (inr ⋅ ) ∈ (T List?))))
Proof
Definitions occuring in Statement : 
bag-remove1: bag-remove1(eq;bs;a)
, 
l_member: (x ∈ l)
, 
reverse: rev(as)
, 
append: as @ bs
, 
cons: [a / b]
, 
nil: []
, 
list: T List
, 
deq: EqDecider(T)
, 
it: ⋅
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
not: ¬A
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
unit: Unit
, 
inr: inr x 
, 
inl: inl x
, 
union: left + right
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
bag-remove1: bag-remove1(eq;bs;a)
, 
or: P ∨ Q
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
top: Top
, 
prop: ℙ
, 
cand: A c∧ B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
guard: {T}
Lemmas referenced : 
bag_remove1_aux_property, 
nil_wf, 
append-nil, 
reverse_wf, 
subtype_rel_list, 
top_wf, 
equal_wf, 
list_wf, 
append_wf, 
cons_wf, 
length_wf, 
length-append, 
exists_wf, 
not_wf, 
l_member_wf, 
equal-wf-T-base, 
unit_wf2, 
bag_remove1_aux_wf, 
deq_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
lambdaFormation, 
dependent_functionElimination, 
cumulativity, 
unionElimination, 
inlFormation, 
productElimination, 
dependent_pairFormation, 
independent_pairFormation, 
promote_hyp, 
sqequalRule, 
applyEquality, 
independent_isectElimination, 
lambdaEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
because_Cache, 
productEquality, 
applyLambdaEquality, 
unionEquality, 
baseClosed, 
inrFormation, 
universeEquality
Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}x:T.  \mforall{}L:T  List.
        ((\mexists{}as,bs:T  List.  ((L  =  ((as  @  [x])  @  bs))  \mwedge{}  (bag-remove1(eq;L;x)  =  (inl  (rev(as)  @  bs)))))
        \mvee{}  ((\mneg{}(x  \mmember{}  L))  \mwedge{}  (bag-remove1(eq;L;x)  =  (inr  \mcdot{}  ))))
Date html generated:
2018_05_21-PM-09_48_06
Last ObjectModification:
2017_07_26-PM-06_30_33
Theory : bags_2
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