Nuprl Lemma : reduce-as-combine-list

∀[A:Type]. ∀[f:A ⟶ A ⟶ A].
  (∀[L:A List]. ∀[z:A].  (reduce(f;z;L) = combine-list(x,y.f[x;y];[z / L]) ∈ A)) 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),  reduce: reduce(f;k;as),  cons: [a / b],  list: T List,  comm: Comm(T;op),  assoc: Assoc(T;op),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s1;s2],  lambda: λx.A[x],  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  so_apply: x[s1;s2],  combine-list: combine-list(x,y.f[x; y];L),  comm: Comm(T;op),  assoc: Assoc(T;op),  infix_ap: x f y,  all: ∀x:A. B[x],  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  and: P ∧ Q,  prop: ℙ,  or: P ∨ Q,  so_lambda: λ2x y.t[x; y],  cons: [a / b],  le: A ≤ B,  less_than': less_than'(a;b),  colength: colength(L),  nil: [],  it: ⋅,  guard: {T},  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_type: SQType(T),  less_than: a < b,  squash: ↓T,  decidable: Dec(P),  subtype_rel: A ⊆r B,  true: True,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  reduce_hd_cons_lemma,  reduce_tl_cons_lemma,  nat_properties,  full-omega-unsat,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  ge_wf,  istype-less_than,  list-cases,  reduce_nil_lemma,  list_accum_nil_lemma,  product_subtype_list,  colength-cons-not-zero,  colength_wf_list,  istype-void,  istype-le,  subtract-1-ge-0,  subtype_base_sq,  intformeq_wf,  int_formula_prop_eq_lemma,  set_subtype_base,  int_subtype_base,  spread_cons_lemma,  decidable__equal_int,  subtract_wf,  intformnot_wf,  itermSubtract_wf,  itermAdd_wf,  int_formula_prop_not_lemma,  int_term_value_subtract_lemma,  int_term_value_add_lemma,  decidable__le,  le_wf,  reduce_cons_lemma,  list_accum_cons_lemma,  equal_wf,  squash_wf,  true_wf,  reduce_wf,  subtype_rel_self,  iff_weakening_equal,  istype-nat,  list_wf,  istype-universe
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  Error :memTop,  hypothesis,  isect_memberFormation_alt,  lambdaFormation_alt,  isectElimination,  hypothesisEquality,  setElimination,  rename,  intWeakElimination,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  independent_pairFormation,  universeIsType,  voidElimination,  isect_memberEquality_alt,  axiomEquality,  isectIsTypeImplies,  inhabitedIsType,  functionIsTypeImplies,  unionElimination,  because_Cache,  promote_hyp,  hypothesis_subsumption,  productElimination,  equalityIstype,  dependent_set_memberEquality_alt,  instantiate,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  imageElimination,  baseApply,  closedConclusion,  baseClosed,  applyEquality,  intEquality,  sqequalBase,  imageMemberEquality,  isectIsType,  functionIsType,  universeEquality,  hyp_replacement

Latex:
\mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  A  {}\mrightarrow{}  A].
    (\mforall{}[L:A  List].  \mforall{}[z:A].    (reduce(f;z;L)  =  combine-list(x,y.f[x;y];[z  /  L])))  supposing 
          (Comm(A;\mlambda{}x,y.  f[x;y])  and 
          Assoc(A;\mlambda{}x,y.  f[x;y]))



Date html generated: 2020_05_19-PM-09_45_07
Last ObjectModification: 2019_12_31-PM-00_13_15

Theory : list_1


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