Nuprl Lemma : member-fset-list-union
∀[T:Type]. ∀eq:EqDecider(T). ∀ss:fset(T) List. ∀x:T.  (x ∈ fset-list-union(eq;ss) 
⇐⇒ (∃s∈ss. x ∈ s))
Proof
Definitions occuring in Statement : 
fset-list-union: fset-list-union(eq;ss)
, 
fset-member: a ∈ s
, 
fset: fset(T)
, 
l_exists: (∃x∈L. P[x])
, 
list: T List
, 
deq: EqDecider(T)
, 
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]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
implies: P 
⇒ Q
, 
fset-list-union: fset-list-union(eq;ss)
, 
top: Top
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
false: False
, 
rev_implies: P 
⇐ Q
, 
subtype_rel: A ⊆r B
, 
or: P ∨ Q
, 
guard: {T}
Lemmas referenced : 
list_induction, 
fset_wf, 
all_wf, 
iff_wf, 
fset-member_wf, 
fset-list-union_wf, 
l_exists_wf, 
l_member_wf, 
list_wf, 
reduce_nil_lemma, 
mem_empty_lemma, 
false_wf, 
l_exists_nil, 
l_exists_wf_nil, 
reduce_cons_lemma, 
or_wf, 
member-fset-union, 
l_exists_cons, 
fset-union_wf, 
cons_wf, 
deq_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
thin, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
setElimination, 
rename, 
setEquality, 
independent_functionElimination, 
dependent_functionElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
introduction, 
independent_pairFormation, 
because_Cache, 
productElimination, 
independent_pairEquality, 
addLevel, 
allFunctionality, 
impliesFunctionality, 
applyEquality, 
unionElimination, 
inlFormation, 
inrFormation, 
cumulativity, 
universeEquality
Latex:
\mforall{}[T:Type]
    \mforall{}eq:EqDecider(T).  \mforall{}ss:fset(T)  List.  \mforall{}x:T.    (x  \mmember{}  fset-list-union(eq;ss)  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}s\mmember{}ss.  x  \mmember{}  s))
Date html generated:
2016_05_14-PM-03_40_34
Last ObjectModification:
2015_12_26-PM-06_41_01
Theory : finite!sets
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