Nuprl Lemma : length_zip

∀[T1,T2:Type]. ∀[as:T1 List]. ∀[bs:T2 List].  ||zip(as;bs)|| = ||as|| ∈ ℤ supposing ||as|| = ||bs|| ∈ ℤ


Proof




Definitions occuring in Statement :  zip: zip(as;bs),  length: ||as||,  list: T List,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  uimplies: b supposing a,  prop: ℙ,  so_apply: x[s],  implies: P ⇒ Q,  zip: zip(as;bs),  list_ind: list_ind,  nil: [],  it: ⋅,  all: ∀x:A. B[x],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  top: Top,  so_apply: x[s1;s2;s3],  squash: ↓T,  guard: {T},  decidable: Dec(P),  or: P ∨ Q,  false: False,  uiff: uiff(P;Q),  and: P ∧ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  not: ¬A,  true: True,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  list_induction,  uall_wf,  list_wf,  isect_wf,  equal_wf,  length_wf,  zip_wf,  equal-wf-base-T,  equal-wf-T-base,  nil_wf,  length_of_nil_lemma,  list_ind_nil_lemma,  equal-wf-base,  length_of_cons_lemma,  cons_wf,  list_ind_cons_lemma,  squash_wf,  true_wf,  add_functionality_wrt_eq,  decidable__equal_int,  add-is-int-iff,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformeq_wf,  itermVar_wf,  itermAdd_wf,  itermConstant_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_var_lemma,  int_term_value_add_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  false_wf,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  cumulativity,  hypothesis,  intEquality,  because_Cache,  productEquality,  independent_functionElimination,  baseClosed,  voidEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  equalityTransitivity,  equalitySymmetry,  lambdaFormation,  rename,  addEquality,  natural_numberEquality,  axiomEquality,  applyEquality,  imageElimination,  independent_isectElimination,  unionElimination,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  productElimination,  dependent_pairFormation,  int_eqEquality,  independent_pairFormation,  computeAll,  imageMemberEquality,  universeEquality

Latex:
\mforall{}[T1,T2:Type].  \mforall{}[as:T1  List].  \mforall{}[bs:T2  List].    ||zip(as;bs)||  =  ||as||  supposing  ||as||  =  ||bs||



Date html generated: 2017_04_17-AM-08_55_08
Last ObjectModification: 2017_02_27-PM-05_10_44

Theory : list_1


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