Nuprl Lemma : rsub-approx
∀[a,b:ℝ]. ∀[n:ℕ+].  ((a - b) n ~ ((a (4 * n)) - b (4 * n)) ÷ 4)
Proof
Definitions occuring in Statement : 
rsub: x - y
, 
real: ℝ
, 
nat_plus: ℕ+
, 
uall: ∀[x:A]. B[x]
, 
apply: f a
, 
divide: n ÷ m
, 
multiply: n * m
, 
subtract: n - m
, 
natural_number: $n
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
rsub: x - y
, 
divide: n ÷ m
, 
rminus: -(x)
, 
subtract: n - m
, 
real: ℝ
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
int_nzero: ℤ-o
, 
true: True
, 
nequal: a ≠ b ∈ T 
, 
sq_type: SQType(T)
, 
guard: {T}
Lemmas referenced : 
subtype_base_sq, 
int_subtype_base, 
radd-approx, 
rminus_wf, 
divide_wfa, 
subtract_wf, 
nat_plus_properties, 
decidable__lt, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
itermMultiply_wf, 
itermVar_wf, 
istype-int, 
int_formula_prop_and_lemma, 
istype-void, 
int_formula_prop_not_lemma, 
int_formula_prop_less_lemma, 
int_term_value_constant_lemma, 
int_term_value_mul_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
istype-less_than, 
nequal_wf, 
nat_plus_wf, 
real_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
thin, 
instantiate, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
cumulativity, 
intEquality, 
independent_isectElimination, 
hypothesis, 
sqequalRule, 
hypothesisEquality, 
applyEquality, 
setElimination, 
rename, 
dependent_set_memberEquality_alt, 
multiplyEquality, 
natural_numberEquality, 
dependent_functionElimination, 
unionElimination, 
approximateComputation, 
independent_functionElimination, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
independent_pairFormation, 
universeIsType, 
because_Cache, 
lambdaFormation_alt, 
equalityTransitivity, 
equalitySymmetry, 
equalityIstype, 
baseClosed, 
sqequalBase, 
axiomSqEquality, 
isectIsTypeImplies, 
inhabitedIsType
Latex:
\mforall{}[a,b:\mBbbR{}].  \mforall{}[n:\mBbbN{}\msupplus{}].    ((a  -  b)  n  \msim{}  ((a  (4  *  n))  -  b  (4  *  n))  \mdiv{}  4)
Date html generated:
2019_10_16-PM-03_07_46
Last ObjectModification:
2019_05_23-PM-05_22_49
Theory : reals
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