Nuprl Lemma : mul-div-bounds
∀[a,b:ℤ]. ∀[m:ℤ-o].  (|(a * (b ÷ m)) - b * (a ÷ m)| ≤ (|a| + |b|))
Proof
Definitions occuring in Statement : 
absval: |i|
, 
int_nzero: ℤ-o
, 
uall: ∀[x:A]. B[x]
, 
le: A ≤ B
, 
divide: n ÷ m
, 
multiply: n * m
, 
subtract: n - m
, 
add: n + m
, 
int: ℤ
Definitions unfolded in proof : 
rev_uimplies: rev_uimplies(P;Q)
, 
ge: i ≥ j 
, 
less_than: a < b
, 
le: A ≤ B
, 
sq_type: SQType(T)
, 
uiff: uiff(P;Q)
, 
or: P ∨ Q
, 
decidable: Dec(P)
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
guard: {T}
, 
true: True
, 
nat: ℕ
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
and: P ∧ Q
, 
top: Top
, 
all: ∀x:A. B[x]
, 
false: False
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
int_nzero: ℤ-o
, 
nequal: a ≠ b ∈ T 
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
le_weakening, 
add_functionality_wrt_le, 
int-triangle-inequality2, 
le_transitivity, 
le_functionality, 
nat_properties, 
equal-wf-base, 
mul_preserves_le, 
int_formula_prop_less_lemma, 
int_formula_prop_le_lemma, 
intformless_wf, 
intformle_wf, 
decidable__le, 
rem_bounds_absval, 
int_nzero_wf, 
less_than'_wf, 
false_wf, 
int_term_value_add_lemma, 
int_term_value_subtract_lemma, 
int_term_value_mul_lemma, 
itermAdd_wf, 
itermSubtract_wf, 
itermMultiply_wf, 
multiply-is-int-iff, 
add-is-int-iff, 
decidable__equal_int, 
int_subtype_base, 
subtype_base_sq, 
iff_weakening_equal, 
nat_wf, 
absval_mul, 
true_wf, 
squash_wf, 
le_wf, 
equal-wf-T-base, 
absval_nat_plus, 
int_formula_prop_wf, 
int_formula_prop_not_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_and_lemma, 
intformnot_wf, 
itermConstant_wf, 
itermVar_wf, 
intformeq_wf, 
intformand_wf, 
full-omega-unsat, 
int_nzero_properties, 
subtract_wf, 
absval_wf, 
mul_cancel_in_le, 
mul_preserves_eq, 
div_rem_sum
Rules used in proof : 
applyLambdaEquality, 
remainderEquality, 
axiomEquality, 
independent_pairEquality, 
closedConclusion, 
baseApply, 
promote_hyp, 
pointwiseFunctionality, 
unionElimination, 
cumulativity, 
instantiate, 
productElimination, 
universeEquality, 
imageMemberEquality, 
imageElimination, 
baseClosed, 
addEquality, 
applyEquality, 
independent_pairFormation, 
sqequalRule, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
dependent_functionElimination, 
intEquality, 
int_eqEquality, 
lambdaEquality, 
dependent_pairFormation, 
independent_functionElimination, 
approximateComputation, 
natural_numberEquality, 
lambdaFormation, 
rename, 
setElimination, 
divideEquality, 
multiplyEquality, 
independent_isectElimination, 
hypothesis, 
equalitySymmetry, 
equalityTransitivity, 
because_Cache, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[a,b:\mBbbZ{}].  \mforall{}[m:\mBbbZ{}\msupminus{}\msupzero{}].    (|(a  *  (b  \mdiv{}  m))  -  b  *  (a  \mdiv{}  m)|  \mleq{}  (|a|  +  |b|))
Date html generated:
2017_09_29-PM-05_57_31
Last ObjectModification:
2017_09_06-PM-01_47_38
Theory : int_2
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