Nuprl Lemma : rsqrt-rmul

x:{x:ℝr0 ≤ x} . ∀[y:{x:ℝr0 ≤ x} ]. ((rsqrt(x) rsqrt(y)) rsqrt(x y))


Proof




Definitions occuring in Statement :  rsqrt: rsqrt(x) rleq: x ≤ y req: y rmul: b int-to-real: r(n) real: 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: subtype_rel: A ⊆B and: P ∧ Q uimplies: supposing a sq_stable: SqStable(P) implies:  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


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