Nuprl Lemma : l_disjoint_cons

∀[T:Type]. ∀[a,b:T List]. ∀[x:T].  uiff(l_disjoint(T;a;[x / b]);(¬(x ∈ a)) ∧ l_disjoint(T;a;b))


Proof




Definitions occuring in Statement :  l_disjoint: l_disjoint(T;l1;l2),  l_member: (x ∈ l),  cons: [a / b],  list: T List,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  not: ¬A,  and: P ∧ Q,  universe: Type
Definitions unfolded in proof :  append: as @ bs,  all: ∀x:A. B[x],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  member: t ∈ T,  top: Top,  so_apply: x[s1;s2;s3],  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  false: False,  prop: ℙ,  uall: ∀[x:A]. B[x],  l_disjoint: l_disjoint(T;l1;l2),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  list_ind_cons_lemma,  list_ind_nil_lemma,  l_member_wf,  and_wf,  not_wf,  l_disjoint_wf,  l_disjoint_singleton,  cons_wf,  nil_wf,  uiff_wf,  iff_weakening_uiff,  append_wf,  l_disjoint_append,  list_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  cut,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isect_memberEquality,  voidElimination,  voidEquality,  hypothesis,  independent_pairFormation,  isect_memberFormation,  introduction,  lambdaFormation,  productElimination,  independent_functionElimination,  isectElimination,  hypothesisEquality,  independent_pairEquality,  lambdaEquality,  because_Cache,  addLevel,  independent_isectElimination,  cumulativity,  universeEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[T:Type].  \mforall{}[a,b:T  List].  \mforall{}[x:T].    uiff(l\_disjoint(T;a;[x  /  b]);(\mneg{}(x  \mmember{}  a))  \mwedge{}  l\_disjoint(T;a;b))



Date html generated: 2016_05_14-AM-07_56_09
Last ObjectModification: 2015_12_26-PM-04_50_30

Theory : list_1


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