Nuprl Lemma : decidable__equal_list

∀[T:Type]. ((∀x,y:T.  Dec(x = y ∈ T)) ⇒ (∀xs,ys:T List.  Dec(xs = ys ∈ (T List))))


Proof




Definitions occuring in Statement :  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],  implies: P ⇒ Q,  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ,  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  and: P ∧ Q,  top: Top,  false: False,  squash: ↓T,  true: True,  cand: A c∧ B,  uimplies: b supposing a,  ge: i ≥ j ,  subtype_rel: A ⊆r B
Lemmas referenced :  tl_wf,  reduce_tl_cons_lemma,  top_wf,  subtype_rel_list,  length_cons_ge_one,  length_wf,  ge_wf,  squash_wf,  hd_wf,  reduce_hd_cons_lemma,  decidable__and2,  cons_neq_nil,  btrue_neq_bfalse,  bfalse_wf,  null_cons_lemma,  null_wf,  and_wf,  btrue_wf,  null_nil_lemma,  not_wf,  cons_wf,  nil_wf,  equal_wf,  decidable_wf,  list_wf,  all_wf,  list_induction
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  hypothesis,  independent_functionElimination,  because_Cache,  rename,  dependent_functionElimination,  universeEquality,  inlFormation,  inrFormation,  dependent_set_memberEquality,  independent_pairFormation,  equalityTransitivity,  equalitySymmetry,  applyEquality,  setElimination,  productElimination,  setEquality,  isect_memberEquality,  voidElimination,  voidEquality,  unionElimination,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  introduction,  independent_isectElimination

Latex:
\mforall{}[T:Type].  ((\mforall{}x,y:T.    Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}xs,ys:T  List.    Dec(xs  =  ys)))



Date html generated: 2016_05_14-AM-07_39_53
Last ObjectModification: 2016_01_15-AM-08_36_41

Theory : list_1


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