Nuprl Lemma : member-intersection

[A:Type]. ∀eq:EqDecider(A). ∀L1,L2:A List. ∀x:A.  ((x ∈ l_intersection(eq;L1;L2)) ⇐⇒ (x ∈ L1) ∧ (x ∈ L2))


Proof




Definitions occuring in Statement :  l_intersection: l_intersection(eq;L1;L2) l_member: (x ∈ l) list: List deq: EqDecider(T) uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] l_intersection: l_intersection(eq;L1;L2) iff: ⇐⇒ Q and: P ∧ Q member: t ∈ T implies:  Q prop: rev_implies:  Q
Lemmas referenced :  assert-deq-member assert_wf deq-member_wf iff_wf and_wf l_member_wf member_filter filter_wf5 list_wf deq_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut sqequalRule addLevel sqequalHypSubstitution productElimination thin independent_pairFormation impliesFunctionality hypothesis lemma_by_obid isectElimination because_Cache dependent_functionElimination hypothesisEquality independent_functionElimination andLevelFunctionality lambdaEquality cumulativity setElimination rename setEquality universeEquality

Latex:
\mforall{}[A:Type]
    \mforall{}eq:EqDecider(A).  \mforall{}L1,L2:A  List.  \mforall{}x:A.    ((x  \mmember{}  l\_intersection(eq;L1;L2))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L1)  \mwedge{}  (x  \mmember{}  L2))



Date html generated: 2016_05_14-PM-03_32_30
Last ObjectModification: 2015_12_26-PM-06_01_25

Theory : decidable!equality


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