Nuprl Lemma : bag_remove1_aux_property
∀[T:Type]
  ∀eq:EqDecider(T). ∀x:T. ∀L,checked:T List.
    ((∃as,bs:T List
       ((L = ((as @ [x]) @ bs) ∈ (T List))
       ∧ (bag_remove1_aux(eq;checked;x;L) = (inl ((rev(as) @ checked) @ bs)) ∈ (T List?))))
    ∨ ((¬(x ∈ L)) ∧ (bag_remove1_aux(eq;checked;x;L) = (inr ⋅ ) ∈ (T List?))))
Proof
Definitions occuring in Statement : 
bag_remove1_aux: bag_remove1_aux(eq;checked;a;as), 
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], 
all: ∀x:A. B[x], 
member: t ∈ T, 
so_lambda: λ2x.t[x], 
prop: ℙ, 
and: P ∧ Q, 
top: Top, 
so_apply: x[s], 
implies: P ⇒ Q, 
bag_remove1_aux: bag_remove1_aux(eq;checked;a;as), 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
so_apply: x[s1;s2;s3], 
deq: EqDecider(T), 
exposed-bfalse: exposed-bfalse, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
uimplies: b supposing a, 
eqof: eqof(d), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
not: ¬A, 
cand: A c∧ B, 
append: as @ bs, 
list_ind: list_ind, 
reverse: rev(as), 
rev-append: rev(as) + bs, 
list_accum: list_accum, 
nil: [], 
squash: ↓T, 
true: True, 
subtype_rel: A ⊆r B, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
list_induction, 
all_wf, 
list_wf, 
or_wf, 
exists_wf, 
equal_wf, 
append_wf, 
cons_wf, 
nil_wf, 
length_wf, 
length-append, 
not_wf, 
l_member_wf, 
equal-wf-T-base, 
unit_wf2, 
bag_remove1_aux_wf, 
list_ind_nil_lemma, 
list_ind_cons_lemma, 
bool_wf, 
eqtt_to_assert, 
safe-assert-deq, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
deq_wf, 
null_nil_lemma, 
btrue_wf, 
member-implies-null-eq-bfalse, 
btrue_neq_bfalse, 
it_wf, 
equal-wf-base-T, 
length_of_nil_lemma, 
reverse_wf, 
and_wf, 
length_of_cons_lemma, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
reverse-cons, 
append_assoc, 
cons_member
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
thin, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
because_Cache, 
sqequalRule, 
lambdaEquality, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
productEquality, 
applyLambdaEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
unionEquality, 
baseClosed, 
independent_functionElimination, 
dependent_functionElimination, 
rename, 
applyEquality, 
setElimination, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
independent_isectElimination, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
universeEquality, 
inrFormation, 
independent_pairFormation, 
inrEquality, 
inlEquality, 
inlFormation, 
dependent_set_memberEquality, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
hyp_replacement
Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}x:T.  \mforall{}L,checked:T  List.
        ((\mexists{}as,bs:T  List
              ((L  =  ((as  @  [x])  @  bs))
              \mwedge{}  (bag\_remove1\_aux(eq;checked;x;L)  =  (inl  ((rev(as)  @  checked)  @  bs)))))
        \mvee{}  ((\mneg{}(x  \mmember{}  L))  \mwedge{}  (bag\_remove1\_aux(eq;checked;x;L)  =  (inr  \mcdot{}  ))))
Date html generated:
2018_05_21-PM-09_48_03
Last ObjectModification:
2017_07_26-PM-06_30_31
Theory : bags_2
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