Nuprl Lemma : bag-subtract-member-if-no-repeats
∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[bs,as:bag(T)]. ∀[x:T].
  uiff(x ↓∈ bag-subtract(eq;bs;as);x ↓∈ bs ∧ (¬x ↓∈ as)) supposing bag-no-repeats(T;bs)
Proof
Definitions occuring in Statement : 
bag-subtract: bag-subtract(eq;bs;as)
, 
bag-member: x ↓∈ bs
, 
bag-no-repeats: bag-no-repeats(T;bs)
, 
bag: bag(T)
, 
deq: EqDecider(T)
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
not: ¬A
, 
and: P ∧ Q
, 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
bag-member: x ↓∈ bs
, 
squash: ↓T
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
sq_stable: SqStable(P)
, 
exists: ∃x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
bag-subtract: bag-subtract(eq;bs;as)
, 
bag-accum: bag-accum(v,x.f[v; x];init;bs)
, 
top: Top
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
empty-bag: {}
, 
sq_or: a ↓∨ b
, 
guard: {T}
, 
or: P ∨ Q
, 
cons-bag: x.b
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
true: True
Lemmas referenced : 
bag-member_wf, 
bag-subtract_wf, 
not_wf, 
bag-no-repeats_wf, 
bag_wf, 
deq_wf, 
uiff_wf, 
squash_wf, 
all_wf, 
bag_to_squash_list, 
sq_stable__all, 
sq_stable__uiff, 
sq_stable__bag-member, 
sq_stable__and, 
sq_stable__not, 
list_induction, 
list-subtype-bag, 
list_wf, 
list_accum_nil_lemma, 
bag-member-empty-iff, 
nil_wf, 
list_accum_cons_lemma, 
bag-drop_wf, 
bag-drop-no-repeats, 
sq_or_wf, 
equal_wf, 
bag-member-cons, 
cons_wf, 
iff_weakening_uiff, 
bag-drop-property, 
true_wf, 
iff_weakening_equal, 
bag-member-append, 
single-bag_wf, 
bag-no-repeats-append, 
bag-member-single
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
productEquality, 
because_Cache, 
universeEquality, 
isect_memberFormation, 
sqequalRule, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
lambdaEquality, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
voidElimination, 
independent_functionElimination, 
functionEquality, 
lambdaFormation, 
promote_hyp, 
rename, 
applyEquality, 
independent_isectElimination, 
hyp_replacement, 
Error :applyLambdaEquality, 
voidEquality, 
independent_pairFormation, 
inrFormation, 
addLevel, 
unionElimination, 
natural_numberEquality, 
inlFormation
Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[bs,as:bag(T)].  \mforall{}[x:T].
    uiff(x  \mdownarrow{}\mmember{}  bag-subtract(eq;bs;as);x  \mdownarrow{}\mmember{}  bs  \mwedge{}  (\mneg{}x  \mdownarrow{}\mmember{}  as))  supposing  bag-no-repeats(T;bs)
Date html generated:
2016_10_25-AM-11_28_31
Last ObjectModification:
2016_07_12-AM-07_35_09
Theory : bags_2
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