Nuprl Lemma : setmem-intersectionset

∀s,x:coSet{i:l}.  ((∃a:coSet{i:l}. (a ∈ s)) ⇒ ((x ∈ ⋂(s)) ⇐⇒ ∀z:coSet{i:l}. ((z ∈ s) ⇒ (x ∈ z))))


Proof




Definitions occuring in Statement :  intersectionset: ⋂(s),  setmem: (x ∈ s),  coSet: coSet{i:l},  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q
Definitions unfolded in proof :  guard: {T},  cand: A c∧ B,  exists: ∃x:A. B[x],  rev_implies: P ⇐ Q,  allsetmem: ∀a∈A.P[a],  set-predicate: set-predicate{i:l}(s;a.P[a]),  so_apply: x[s],  prop: ℙ,  so_lambda: λ2x.t[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  and: P ∧ Q,  iff: P ⇐⇒ Q,  intersectionset: ⋂(s),  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  setmem-unionset,  seteq_weakening,  setmem_functionality,  allsetmem-iff,  exists_wf,  all_wf,  iff_wf,  sub-set_wf,  seteq_wf,  set-item_wf,  setmem_functionality_1,  coSet_wf,  setmem_wf,  allsetmem_wf,  unionset_wf,  setmem-sub-coset
Rules used in proof :  andLevelFunctionality,  because_Cache,  dependent_pairFormation,  functionEquality,  productEquality,  instantiate,  allLevelFunctionality,  promote_hyp,  levelHypothesis,  allFunctionality,  independent_functionElimination,  cumulativity,  setEquality,  rename,  setElimination,  lambdaEquality,  sqequalRule,  hypothesis,  hypothesisEquality,  isectElimination,  dependent_functionElimination,  extract_by_obid,  introduction,  impliesFunctionality,  independent_pairFormation,  thin,  productElimination,  sqequalHypSubstitution,  addLevel,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}s,x:coSet\{i:l\}.    ((\mexists{}a:coSet\{i:l\}.  (a  \mmember{}  s))  {}\mRightarrow{}  ((x  \mmember{}  \mcap{}(s))  \mLeftarrow{}{}\mRightarrow{}  \mforall{}z:coSet\{i:l\}.  ((z  \mmember{}  s)  {}\mRightarrow{}  (x  \mmember{}  z))))



Date html generated: 2018_07_29-AM-10_01_02
Last ObjectModification: 2018_07_18-PM-02_50_25

Theory : constructive!set!theory


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