Nuprl Lemma : firstn-iseg

∀[T:Type]. ∀L:T List. ∀n:ℕ.  firstn(n;L) ≤ L


Proof




Definitions occuring in Statement :  iseg: l1 ≤ l2,  firstn: firstn(n;as),  list: T List,  nat: ℕ,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  nat: ℕ,  so_apply: x[s],  implies: P ⇒ Q,  prop: ℙ,  firstn: firstn(n;as),  so_lambda: so_lambda(x,y,z.t[x; y; z]),  top: Top,  so_apply: x[s1;s2;s3],  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A,  cand: A c∧ B,  ge: i ≥ j ,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  list_induction,  all_wf,  nat_wf,  iseg_wf,  firstn_wf,  list_wf,  list_ind_nil_lemma,  nil_iseg,  nil_wf,  list_ind_cons_lemma,  lt_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  less_than_wf,  cons_wf,  subtract_wf,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermSubtract_wf,  itermVar_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_subtract_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  le_wf,  cons_iseg
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  hypothesis,  cumulativity,  setElimination,  rename,  independent_functionElimination,  because_Cache,  dependent_functionElimination,  universeEquality,  isect_memberEquality,  voidElimination,  voidEquality,  natural_numberEquality,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  dependent_pairFormation,  promote_hyp,  instantiate,  independent_pairFormation,  dependent_set_memberEquality,  int_eqEquality,  intEquality,  computeAll

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}n:\mBbbN{}.    firstn(n;L)  \mleq{}  L



Date html generated: 2017_04_17-AM-08_01_52
Last ObjectModification: 2017_02_27-PM-04_32_00

Theory : list_1


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