Nuprl Lemma : div_floor_bounds

∀[a:ℤ]. ∀[n:ℤ-o].
  ((((a ÷↓ n) * n) ≤ a) ∧ a < ((a ÷↓ n) + 1) * n supposing 0 < n
  ∧ ((a ÷↓ n) + 1) * n < a ∧ (a ≤ ((a ÷↓ n) * n)) supposing n < 0)


Proof




Definitions occuring in Statement :  div_floor: a ÷↓ n,  int_nzero: ℤ-o,  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  le: A ≤ B,  and: P ∧ Q,  multiply: n * m,  add: n + m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  div_floor: a ÷↓ n,  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  not: ¬A,  implies: P ⇒ Q,  false: False,  prop: ℙ,  all: ∀x:A. B[x],  sq_type: SQType(T),  guard: {T},  and: P ∧ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  less_than: a < b,  less_than': less_than'(a;b),  top: Top,  true: True,  squash: ↓T,  cand: A c∧ B,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  le: A ≤ B,  subtype_rel: A ⊆r B,  nat: ℕ,  has-value: (a)↓,  int_lower: {...i},  gt: i > j,  subtract: n - m,  so_lambda: λ2x.t[x],  so_apply: x[s],  decidable: Dec(P)
Lemmas referenced :  value-type-has-value,  int-value-type,  equal_wf,  div_rem_sum,  rem_bounds_z,  subtype_base_sq,  int_subtype_base,  lt_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  top_wf,  less_than_wf,  less_than_transitivity2,  le_weakening2,  less_than_irreflexivity,  eqff_to_assert,  bool_cases_sqequal,  bool_subtype_base,  iff_transitivity,  assert_wf,  bnot_wf,  not_wf,  iff_weakening_uiff,  assert_of_bnot,  less_than'_wf,  subtract_wf,  member-less_than,  equal-wf-base-T,  absval_wf,  nat_wf,  div_floor_wf,  int_nzero_wf,  squash_wf,  true_wf,  absval_neg,  le_wf,  absval_pos,  not-gt-2,  add_functionality_wrt_lt,  le_reflexive,  minus-one-mul-top,  add-associates,  minus-one-mul,  add-swap,  add-mul-special,  zero-mul,  zero-add,  mul-commutes,  add-commutes,  mul-distributes-right,  one-mul,  not-lt-2,  add_functionality_wrt_le,  add-is-int-iff,  set_subtype_base,  nequal_wf,  multiply-is-int-iff,  decidable__le,  false_wf,  not-le-2,  less-iff-le,  condition-implies-le,  minus-add,  minus-zero,  le-add-cancel2,  add-zero,  two-mul,  decidable__lt,  le-add-cancel-alt,  mul-associates,  le-add-cancel
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  intEquality,  independent_isectElimination,  hypothesis,  remainderEquality,  hypothesisEquality,  setElimination,  rename,  because_Cache,  lambdaFormation,  independent_functionElimination,  voidElimination,  natural_numberEquality,  divideEquality,  instantiate,  cumulativity,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_pairFormation,  isect_memberFormation,  unionElimination,  equalityElimination,  productElimination,  sqequalRule,  lessCases,  axiomSqEquality,  isect_memberEquality,  voidEquality,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_pairFormation,  promote_hyp,  impliesFunctionality,  independent_pairEquality,  lambdaEquality,  addEquality,  multiplyEquality,  axiomEquality,  applyEquality,  callbyvalueReduce,  addLevel,  hyp_replacement,  dependent_set_memberEquality,  levelHypothesis,  minusEquality,  baseApply,  closedConclusion

Latex:
\mforall{}[a:\mBbbZ{}].  \mforall{}[n:\mBbbZ{}\msupminus{}\msupzero{}].
    ((((a  \mdiv{}\mdownarrow{}  n)  *  n)  \mleq{}  a)  \mwedge{}  a  <  ((a  \mdiv{}\mdownarrow{}  n)  +  1)  *  n  supposing  0  <  n
    \mwedge{}  ((a  \mdiv{}\mdownarrow{}  n)  +  1)  *  n  <  a  \mwedge{}  (a  \mleq{}  ((a  \mdiv{}\mdownarrow{}  n)  *  n))  supposing  n  <  0)



Date html generated: 2019_06_20-AM-11_25_49
Last ObjectModification: 2018_08_20-PM-09_28_54

Theory : arithmetic


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