Nuprl Lemma : decidable__l_member

∀[A:Type]. ∀x:A. ((∀x,y:A.  Dec(x = y ∈ A)) ⇒ (∀L:A List. Dec((x ∈ L))))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  list: T List,  decidable: Dec(P),  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  prop: ℙ
Lemmas referenced :  list_induction,  decidable_wf,  l_member_wf,  list_wf,  decidable_functionality,  nil_wf,  false_wf,  nil_member,  decidable__false,  cons_wf,  or_wf,  equal_wf,  cons_member,  decidable__or,  all_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  because_Cache,  sqequalRule,  lambdaEquality,  hypothesisEquality,  hypothesis,  independent_functionElimination,  dependent_functionElimination,  productElimination,  rename,  universeEquality

Latex:
\mforall{}[A:Type].  \mforall{}x:A.  ((\mforall{}x,y:A.    Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}L:A  List.  Dec((x  \mmember{}  L))))



Date html generated: 2016_05_14-AM-06_43_14
Last ObjectModification: 2015_12_26-PM-00_28_44

Theory : list_0


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