Nuprl Lemma : arith-geom-mean-inequality

∀x,y:{t:ℝ| r0 ≤ t} .  ((rsqrt(x * y) ≤ (x + y/r(2))) ∧ (x ≠ y ⇒ (rsqrt(x * y) < (x + y/r(2)))))


Proof




Definitions occuring in Statement :  rsqrt: rsqrt(x),  rdiv: (x/y),  rneq: x ≠ y,  rleq: x ≤ y,  rless: x < y,  rmul: a * b,  radd: a + b,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  uimplies: b supposing a,  implies: P ⇒ Q,  rsub: x - y,  and: P ∧ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  rneq: x ≠ y,  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  guard: {T},  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  sq_stable: SqStable(P),  subtype_rel: A ⊆r B,  le: A ≤ B,  false: False,  not: ¬A,  rge: x ≥ y,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  sq_type: SQType(T),  rless: x < y,  sq_exists: ∃x:{A| B[x]},  nat_plus: ℕ+
Lemmas referenced :  set_wf,  real_wf,  rleq_wf,  int-to-real_wf,  req_wf,  rmul_wf,  rsub_wf,  radd_wf,  rminus_wf,  req_weakening,  uiff_transitivity,  req_functionality,  req_transitivity,  rmul-distrib,  radd_functionality,  rmul_over_rminus,  rminus_functionality,  rmul_comm,  rminus-rminus,  req_inversion,  radd-assoc,  radd_comm,  radd-ac,  rminus-as-rmul,  rmul-distrib2,  rmul_functionality,  radd-int,  rmul-identity1,  rmul-assoc,  square-nonneg,  radd-preserves-rless,  rless_wf,  square-nonzero,  rless_transitivity2,  rless_transitivity1,  rneq_wf,  rless_functionality,  radd-zero-both,  radd-rminus-both,  rleq_functionality,  rmul_preserves_rleq,  rdiv_wf,  rless-int,  rmul_preserves_rless,  rsqrt_wf,  rmul-nonneg-case1,  sq_stable__rleq,  rmul-rdiv-cancel2,  radd-preserves-rleq,  rmul-zero-both,  rleq-int,  false_wf,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  rsqrt_functionality_wrt_rleq,  radd-non-neg,  rsqrt-of-square,  rsqrt-rmul,  subtype_base_sq,  int_subtype_base,  decidable__equal_int,  satisfiable-full-omega-tt,  intformnot_wf,  intformeq_wf,  itermConstant_wf,  itermMultiply_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_constant_lemma,  int_term_value_mul_lemma,  int_formula_prop_wf,  rsqrt_functionality,  rmul-int,  rsqrt_functionality_wrt_rless,  nat_plus_properties
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesis,  sqequalRule,  lambdaEquality,  natural_numberEquality,  hypothesisEquality,  setElimination,  rename,  because_Cache,  minusEquality,  addEquality,  independent_isectElimination,  independent_functionElimination,  productElimination,  unionElimination,  inlFormation,  dependent_functionElimination,  inrFormation,  addLevel,  levelHypothesis,  promote_hyp,  independent_pairFormation,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_set_memberEquality,  applyEquality,  equalityTransitivity,  equalitySymmetry,  setEquality,  productEquality,  instantiate,  cumulativity,  intEquality,  dependent_pairFormation,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  multiplyEquality

Latex:
\mforall{}x,y:\{t:\mBbbR{}|  r0  \mleq{}  t\}  .    ((rsqrt(x  *  y)  \mleq{}  (x  +  y/r(2)))  \mwedge{}  (x  \mneq{}  y  {}\mRightarrow{}  (rsqrt(x  *  y)  <  (x  +  y/r(2)))))



Date html generated: 2016_10_26-AM-10_14_06
Last ObjectModification: 2016_09_07-AM-00_15_59

Theory : reals


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