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
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