Nuprl Lemma : derivative-mul

I:Interval. ∀f1,f2:I ⟶ℝ. ∀g1,g2:{h:I ⟶ℝ| ∀x,y:{t:ℝt ∈ I} .  ((x y)  ((h x) (h y)))} .
  (d(f1[x])/dx = λx.g1[x] on I
   d(f2[x])/dx = λx.g2[x] on I
   d(f1[x] f2[x])/dx = λx.(f1[x] g2[x]) (f2[x] g1[x]) on I)


Proof




Definitions occuring in Statement :  derivative: d(f[x])/dx = λz.g[z] on I rfun: I ⟶ℝ i-member: r ∈ I interval: Interval req: y rmul: b radd: b real: so_apply: x[s] all: x:A. B[x] implies:  Q set: {x:A| B[x]}  apply: a
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q so_apply: x[s] member: t ∈ T true: True so_lambda: λ2x.t[x] rfun: I ⟶ℝ uall: [x:A]. B[x] prop: subtype_rel: A ⊆B label: ...$L... t sq_stable: SqStable(P) squash: T r-ap: f(x) guard: {T}
Lemmas referenced :  derivative-mul-part1 i-member_wf real_wf derivative_wf set_wf rfun_wf all_wf req_wf interval_wf differentiable-continuous sq_stable__req function-proper-continuous sq_stable__all req_witness squash_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation sqequalHypSubstitution sqequalRule cut introduction extract_by_obid dependent_functionElimination thin hypothesisEquality independent_functionElimination natural_numberEquality hypothesis lambdaEquality applyEquality setElimination rename dependent_set_memberEquality isectElimination setEquality functionEquality because_Cache imageMemberEquality baseClosed imageElimination

Latex:
\mforall{}I:Interval.  \mforall{}f1,f2:I  {}\mrightarrow{}\mBbbR{}.  \mforall{}g1,g2:\{h:I  {}\mrightarrow{}\mBbbR{}|  \mforall{}x,y:\{t:\mBbbR{}|  t  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  ((h  x)  =  (h  y)))\}  .
    (d(f1[x])/dx  =  \mlambda{}x.g1[x]  on  I
    {}\mRightarrow{}  d(f2[x])/dx  =  \mlambda{}x.g2[x]  on  I
    {}\mRightarrow{}  d(f1[x]  *  f2[x])/dx  =  \mlambda{}x.(f1[x]  *  g2[x])  +  (f2[x]  *  g1[x])  on  I)



Date html generated: 2016_10_26-AM-11_22_17
Last ObjectModification: 2016_08_28-PM-10_42_53

Theory : reals


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