Nuprl Lemma : member-list-diff

∀[T:Type]. ∀eq:EqDecider(T). ∀as,bs:T List. ∀x:T.  ((x ∈ as-bs) ⇐⇒ (x ∈ as) ∧ (¬(x ∈ bs)))


Proof




Definitions occuring in Statement :  list-diff: as-bs,  l_member: (x ∈ l),  list: T List,  deq: EqDecider(T),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  not: ¬A,  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  and: P ∧ Q
Lemmas referenced :  list-diff-property,  list_wf,  deq_wf
Rules used in proof :  cut,  lemma_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaFormation,  dependent_functionElimination,  productElimination,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}eq:EqDecider(T).  \mforall{}as,bs:T  List.  \mforall{}x:T.    ((x  \mmember{}  as-bs)  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  as)  \mwedge{}  (\mneg{}(x  \mmember{}  bs)))



Date html generated: 2016_05_14-PM-03_29_52
Last ObjectModification: 2015_12_26-PM-06_02_51

Theory : decidable!equality


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