Nuprl Lemma : omega-dark-shadow

∀a,b:ℕ+. ∀c,d:ℤ.  ((((a - 1) * (b - 1)) ≤ ((a * d) - b * c)) ⇒ (∃x:ℤ. ((c ≤ (a * x)) ∧ ((b * x) ≤ d))))


Proof




Definitions occuring in Statement :  nat_plus: ℕ+,  le: A ≤ B,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  multiply: n * m,  subtract: n - m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  nat_plus: ℕ+,  nat: ℕ,  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  and: P ∧ Q,  subtype_rel: A ⊆r B,  int_nzero: ℤ-o,  so_lambda: λ2x.t[x],  so_apply: x[s],  nequal: a ≠ b ∈ T ,  guard: {T},  le: A ≤ B,  cand: A c∧ B,  uiff: uiff(P;Q),  less_than: a < b,  squash: ↓T,  int_lower: {...i},  gt: i > j,  ge: i ≥ j 
Lemmas referenced :  le_wf,  subtract_wf,  nat_plus_wf,  mul_bounds_1a,  nat_plus_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,  itermMultiply_wf,  int_term_value_mul_lemma,  mul_nat_plus,  equal_wf,  div_rem_sum,  subtype_rel_sets,  less_than_wf,  nequal_wf,  intformeq_wf,  int_formula_prop_eq_lemma,  equal-wf-base,  int_subtype_base,  rem_bounds_1,  decidable__equal_int,  decidable__lt,  add-is-int-iff,  multiply-is-int-iff,  itermAdd_wf,  int_term_value_add_lemma,  false_wf,  rem_bounds_2,  itermMinus_wf,  int_term_value_minus_lemma,  not_wf,  mul_preserves_le,  nat_plus_subtype_nat,  mul_cancel_in_le
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  multiplyEquality,  setElimination,  rename,  hypothesisEquality,  hypothesis,  natural_numberEquality,  because_Cache,  intEquality,  dependent_set_memberEquality,  dependent_functionElimination,  unionElimination,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  independent_pairFormation,  computeAll,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  applyEquality,  setEquality,  applyLambdaEquality,  baseClosed,  productElimination,  divideEquality,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  addEquality,  productEquality,  imageElimination

Latex:
\mforall{}a,b:\mBbbN{}\msupplus{}.  \mforall{}c,d:\mBbbZ{}.
    ((((a  -  1)  *  (b  -  1))  \mleq{}  ((a  *  d)  -  b  *  c))  {}\mRightarrow{}  (\mexists{}x:\mBbbZ{}.  ((c  \mleq{}  (a  *  x))  \mwedge{}  ((b  *  x)  \mleq{}  d))))



Date html generated: 2017_04_14-AM-09_15_25
Last ObjectModification: 2017_02_27-PM-03_53_46

Theory : int_2


Home Index