Nuprl Lemma : deq-member-append

∀[A:Type]. ∀[eq:EqDecider(A)]. ∀[L1,L2:A List]. ∀[x:A].  (x ∈b L1 @ L2 ~ x ∈b L1 ∨bx ∈b L2)


Proof




Definitions occuring in Statement :  deq-member: x ∈b L,  append: as @ bs,  list: T List,  deq: EqDecider(T),  bor: p ∨bq,  uall: ∀[x:A]. B[x],  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  all: ∀x:A. B[x],  prop: ℙ,  rev_implies: P ⇐ Q,  sq_type: SQType(T),  guard: {T}
Lemmas referenced :  subtype_base_sq,  bool_subtype_base,  iff_imp_equal_bool,  deq-member_wf,  append_wf,  bor_wf,  iff_transitivity,  assert_wf,  or_wf,  l_member_wf,  iff_weakening_uiff,  assert_of_bor,  assert-deq-member,  member_append,  list_wf,  deq_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  instantiate,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  because_Cache,  independent_isectElimination,  hypothesis,  hypothesisEquality,  independent_pairFormation,  lambdaFormation,  independent_functionElimination,  dependent_functionElimination,  orFunctionality,  productElimination,  equalityTransitivity,  equalitySymmetry,  sqequalAxiom,  sqequalRule,  isect_memberEquality,  universeEquality

Latex:
\mforall{}[A:Type].  \mforall{}[eq:EqDecider(A)].  \mforall{}[L1,L2:A  List].  \mforall{}[x:A].    (x  \mmember{}\msubb{}  L1  @  L2  \msim{}  x  \mmember{}\msubb{}  L1  \mvee{}\msubb{}x  \mmember{}\msubb{}  L2)



Date html generated: 2016_05_14-AM-06_53_26
Last ObjectModification: 2015_12_26-PM-00_20_57

Theory : list_0


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