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: ⇐⇒ Q implies:  Q
Definitions unfolded in proof :  guard: {T} cand: c∧ B exists: x:A. B[x] rev_implies:  Q allsetmem: a∈A.P[a] set-predicate: set-predicate{i:l}(s;a.P[a]) so_apply: x[s] prop: so_lambda: λ2x.t[x] uall: [x:A]. B[x] member: t ∈ T and: P ∧ Q iff: ⇐⇒ Q intersectionset: (s) implies:  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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