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: List deq: EqDecider(T) uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ 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: so_apply: x[s] implies:  Q fset-list-union: fset-list-union(eq;ss) top: Top iff: ⇐⇒ Q and: P ∧ Q false: False rev_implies:  Q subtype_rel: A ⊆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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