Nuprl Lemma : length_segment

∀[T:Type]. ∀[as:T List]. ∀[i:{0...||as||}]. ∀[j:{i...||as||}].  (||as[i..j-]|| = (j - i) ∈ ℤ)


Proof




Definitions occuring in Statement :  segment: as[m..n-],  length: ||as||,  list: T List,  int_iseg: {i...j},  uall: ∀[x:A]. B[x],  subtract: n - m,  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  member: t ∈ T,  uall: ∀[x:A]. B[x],  int_iseg: {i...j},  segment: as[m..n-],  and: P ∧ Q,  cand: A c∧ B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  exists: ∃x:A. B[x],  subtype_rel: A ⊆r B,  nat: ℕ,  so_lambda: λ2x.t[x],  so_apply: x[s],  uimplies: b supposing a,  prop: ℙ,  squash: ↓T,  true: True,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  le: A ≤ B,  subtract: n - m,  top: Top,  uiff: uiff(P;Q),  nat_plus: ℕ+,  less_than: a < b,  less_than': less_than'(a;b),  not: ¬A,  false: False,  decidable: Dec(P),  or: P ∨ Q
Lemmas referenced :  int_iseg_wf,  length_wf,  list_wf,  length_firstn,  nth_tl_wf,  subtract_wf,  non_neg_length,  length_wf_nat,  nat_wf,  set_subtype_base,  le_wf,  int_subtype_base,  equal_wf,  squash_wf,  true_wf,  length_nth_tl,  iff_weakening_equal,  minus-one-mul,  add-commutes,  not-le-2,  add_functionality_wrt_le,  le_reflexive,  minus-one-mul-top,  add-associates,  minus-zero,  add-zero,  one-mul,  zero-add,  add-swap,  add-mul-special,  zero-mul,  two-mul,  mul-distributes-right,  omega-shadow,  less_than_wf,  mul-distributes,  mul-associates,  le-add-cancel,  add-is-int-iff,  minus-add,  mul-commutes,  le-add-cancel-alt,  int_iseg_properties,  nat_properties,  decidable__le
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  hypothesisEquality,  hypothesis,  cumulativity,  because_Cache,  natural_numberEquality,  universeEquality,  isect_memberFormation,  sqequalRule,  isect_memberEquality,  axiomEquality,  dependent_set_memberEquality,  lambdaFormation,  dependent_pairFormation,  sqequalIntensionalEquality,  applyEquality,  intEquality,  lambdaEquality,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  dependent_functionElimination,  independent_functionElimination,  productElimination,  promote_hyp,  independent_pairFormation,  imageElimination,  imageMemberEquality,  baseClosed,  productEquality,  voidElimination,  voidEquality,  addEquality,  multiplyEquality,  minusEquality,  baseApply,  closedConclusion,  unionElimination

Latex:
\mforall{}[T:Type].  \mforall{}[as:T  List].  \mforall{}[i:\{0...||as||\}].  \mforall{}[j:\{i...||as||\}].    (||as[i..j\msupminus{}]||  =  (j  -  i))



Date html generated: 2017_04_14-AM-08_47_46
Last ObjectModification: 2017_02_27-PM-03_34_47

Theory : list_0


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