Nuprl Lemma : l_exists_wf

∀[T:Type]. ∀[L:T List]. ∀[P:{x:T| (x ∈ L)}  ⟶ ℙ].  ((∃x∈L. P[x]) ∈ ℙ)


Proof




Definitions occuring in Statement :  l_exists: (∃x∈L. P[x]),  l_member: (x ∈ l),  list: T List,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  member: t ∈ T,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  l_exists: (∃x∈L. P[x]),  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ,  uimplies: b supposing a,  int_seg: {i..j-},  sq_stable: SqStable(P),  implies: P ⇒ Q,  lelt: i ≤ j < k,  and: P ∧ Q,  squash: ↓T
Lemmas referenced :  list_wf,  sq_stable__le,  list-subtype,  l_member_wf,  select_wf,  length_wf,  int_seg_wf,  exists_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  natural_numberEquality,  cumulativity,  hypothesisEquality,  hypothesis,  lambdaEquality,  applyEquality,  setEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  setElimination,  rename,  independent_functionElimination,  productElimination,  imageMemberEquality,  baseClosed,  imageElimination,  axiomEquality,  functionEquality,  universeEquality,  isect_memberEquality

Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbP{}].    ((\mexists{}x\mmember{}L.  P[x])  \mmember{}  \mBbbP{})



Date html generated: 2016_05_14-AM-06_39_36
Last ObjectModification: 2016_01_14-PM-08_21_14

Theory : list_0


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