Nuprl Lemma : combine-list-append

∀[A:Type]. ∀[f:A ⟶ A ⟶ A].
  (∀[as,bs:A List].
     combine-list(x,y.f[x;y];as @ bs) = combine-list(x,y.f[x;y];bs @ as) ∈ A supposing 0 < ||as @ bs||) supposing 
     (Comm(A;λx,y. f[x;y]) and 
     Assoc(A;λx,y. f[x;y]))


Proof




Definitions occuring in Statement :  combine-list: combine-list(x,y.f[x; y];L),  length: ||as||,  append: as @ bs,  list: T List,  comm: Comm(T;op),  assoc: Assoc(T;op),  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s1;s2],  lambda: λx.A[x],  function: x:A ⟶ B[x],  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  or: P ∨ Q,  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  top: Top,  so_apply: x[s1;s2;s3],  squash: ↓T,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  cons: [a / b],  combine-list: combine-list(x,y.f[x; y];L),  prop: ℙ,  so_apply: x[s],  true: True,  subtype_rel: A ⊆r B,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  comm: Comm(T;op),  infix_ap: x f y
Lemmas referenced :  list-cases,  list_ind_nil_lemma,  combine-list_wf,  append_back_nil,  product_subtype_list,  list_ind_cons_lemma,  length_of_cons_lemma,  cons_wf,  reduce_hd_cons_lemma,  reduce_tl_cons_lemma,  less_than_wf,  length_wf,  append_wf,  comm_wf,  assoc_wf,  equal_wf,  squash_wf,  true_wf,  iff_weakening_equal,  list_accum_cons_lemma,  list_accum_wf,  list_accum_permute
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesisEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesis,  dependent_functionElimination,  unionElimination,  sqequalRule,  isect_memberEquality,  voidElimination,  voidEquality,  applyEquality,  lambdaEquality,  imageElimination,  because_Cache,  independent_isectElimination,  functionExtensionality,  imageMemberEquality,  baseClosed,  promote_hyp,  hypothesis_subsumption,  productElimination,  natural_numberEquality,  cumulativity,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  universeEquality,  independent_functionElimination,  hyp_replacement,  applyLambdaEquality

Latex:
\mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  A  {}\mrightarrow{}  A].
    (\mforall{}[as,bs:A  List].
          combine-list(x,y.f[x;y];as  @  bs)  =  combine-list(x,y.f[x;y];bs  @  as) 
          supposing  0  <  ||as  @  bs||)  supposing 
          (Comm(A;\mlambda{}x,y.  f[x;y])  and 
          Assoc(A;\mlambda{}x,y.  f[x;y]))



Date html generated: 2017_04_17-AM-07_38_52
Last ObjectModification: 2017_02_27-PM-04_12_50

Theory : list_1


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