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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