Nuprl Lemma : derivative-mul

∀I:Interval. ∀f1,f2:I ⟶ℝ. ∀g1,g2:{h:I ⟶ℝ| ∀x,y:{t:ℝ| t ∈ 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: x = y,  rmul: a * b,  radd: a + b,  real: ℝ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  apply: f a
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  so_apply: x[s],  member: t ∈ T,  true: True,  so_lambda: λ2x.t[x],  rfun: I ⟶ℝ,  uall: ∀[x:A]. B[x],  prop: ℙ,  subtype_rel: A ⊆r 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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