Nuprl Lemma : rsqrt-rmul

∀x:{x:ℝ| r0 ≤ x} . ∀[y:{x:ℝ| r0 ≤ x} ]. ((rsqrt(x) * rsqrt(y)) = rsqrt(x * y))


Proof




Definitions occuring in Statement :  rsqrt: rsqrt(x),  rleq: x ≤ y,  req: x = y,  rmul: a * b,  int-to-real: r(n),  real: ℝ,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  prop: ℙ,  subtype_rel: A ⊆r B,  and: P ∧ Q,  uimplies: b supposing a,  sq_stable: SqStable(P),  implies: P ⇒ Q,  squash: ↓T,  so_lambda: λ2x.t[x],  so_apply: x[s],  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  req_witness,  rmul_wf,  rsqrt_wf,  rleq_wf,  int-to-real_wf,  real_wf,  req_wf,  rmul-nonneg-case1,  sq_stable__rleq,  set_wf,  rsqrt-unique,  rsqrt_nonneg,  req_functionality,  req_transitivity,  real_term_polynomial,  itermSubtract_wf,  itermMultiply_wf,  itermVar_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_var_lemma,  req-iff-rsub-is-0,  rmul_functionality,  req_weakening,  rsqrt_squared,  rmul-assoc
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  dependent_set_memberEquality,  hypothesisEquality,  hypothesis,  natural_numberEquality,  applyEquality,  lambdaEquality,  setEquality,  productEquality,  sqequalRule,  because_Cache,  independent_isectElimination,  independent_pairFormation,  independent_functionElimination,  imageMemberEquality,  baseClosed,  imageElimination,  dependent_functionElimination,  computeAll,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  productElimination

Latex:
\mforall{}x:\{x:\mBbbR{}|  r0  \mleq{}  x\}  .  \mforall{}[y:\{x:\mBbbR{}|  r0  \mleq{}  x\}  ].  ((rsqrt(x)  *  rsqrt(y))  =  rsqrt(x  *  y))



Date html generated: 2017_10_03-AM-10_43_55
Last ObjectModification: 2017_07_28-AM-08_18_45

Theory : reals


Home Index