Step
*
1
of Lemma
derivative-rinv
1. I : Interval
2. f : I ⟶ℝ
3. g : I ⟶ℝ
4. ∀x,y:{t:ℝ| t ∈ I} . ((x = y)
⇒ (g[x] = g[y]))
5. d(f[x])/dx = λx.g[x] on I
6. k : ℕ+
7. n : {n:ℕ+| icompact(i-approx(I;n)) ∧ iproper(i-approx(I;n))}
8. ∀a,b:{x:ℝ| x ∈ i-approx(I;n)} . ((a = b)
⇒ (f[a] = f[b]))
9. i-approx(I;n) ⊆ I
10. ∀x:ℝ. ((x ∈ I)
⇒ f[x] ≠ r0)
11. ∃c:ℝ [((r0 < c) ∧ (∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ (c ≤ |f[x]|))))]
12. (r1/f[x]) continuous for x ∈ i-approx(I;n)
13. g[x] continuous for x ∈ i-approx(I;n)
14. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ f[x] ≠ r0)
⊢ ∃del:ℝ [((r0 < del)
∧ (∀x,y:ℝ.
((x ∈ i-approx(I;n))
⇒ (y ∈ i-approx(I;n))
⇒ (|y - x| ≤ del)
⇒ (|(r1/f[y]) - (r1/f[x]) - (-(g[x])/f[x] * f[x]) * (y - x)| ≤ ((r1/r(k)) * |y - x|)))))]
BY
{ Assert ⌜∃M:ℕ+. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ ((|g[x]| ≤ r(M)) ∧ (|(r1/f[x])| ≤ r(M))))⌝⋅ }
1
.....assertion.....
1. I : Interval
2. f : I ⟶ℝ
3. g : I ⟶ℝ
4. ∀x,y:{t:ℝ| t ∈ I} . ((x = y)
⇒ (g[x] = g[y]))
5. d(f[x])/dx = λx.g[x] on I
6. k : ℕ+
7. n : {n:ℕ+| icompact(i-approx(I;n)) ∧ iproper(i-approx(I;n))}
8. ∀a,b:{x:ℝ| x ∈ i-approx(I;n)} . ((a = b)
⇒ (f[a] = f[b]))
9. i-approx(I;n) ⊆ I
10. ∀x:ℝ. ((x ∈ I)
⇒ f[x] ≠ r0)
11. ∃c:ℝ [((r0 < c) ∧ (∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ (c ≤ |f[x]|))))]
12. (r1/f[x]) continuous for x ∈ i-approx(I;n)
13. g[x] continuous for x ∈ i-approx(I;n)
14. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ f[x] ≠ r0)
⊢ ∃M:ℕ+. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ ((|g[x]| ≤ r(M)) ∧ (|(r1/f[x])| ≤ r(M))))
2
1. I : Interval
2. f : I ⟶ℝ
3. g : I ⟶ℝ
4. ∀x,y:{t:ℝ| t ∈ I} . ((x = y)
⇒ (g[x] = g[y]))
5. d(f[x])/dx = λx.g[x] on I
6. k : ℕ+
7. n : {n:ℕ+| icompact(i-approx(I;n)) ∧ iproper(i-approx(I;n))}
8. ∀a,b:{x:ℝ| x ∈ i-approx(I;n)} . ((a = b)
⇒ (f[a] = f[b]))
9. i-approx(I;n) ⊆ I
10. ∀x:ℝ. ((x ∈ I)
⇒ f[x] ≠ r0)
11. ∃c:ℝ [((r0 < c) ∧ (∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ (c ≤ |f[x]|))))]
12. (r1/f[x]) continuous for x ∈ i-approx(I;n)
13. g[x] continuous for x ∈ i-approx(I;n)
14. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ f[x] ≠ r0)
15. ∃M:ℕ+. ∀x:ℝ. ((x ∈ i-approx(I;n))
⇒ ((|g[x]| ≤ r(M)) ∧ (|(r1/f[x])| ≤ r(M))))
⊢ ∃del:ℝ [((r0 < del)
∧ (∀x,y:ℝ.
((x ∈ i-approx(I;n))
⇒ (y ∈ i-approx(I;n))
⇒ (|y - x| ≤ del)
⇒ (|(r1/f[y]) - (r1/f[x]) - (-(g[x])/f[x] * f[x]) * (y - x)| ≤ ((r1/r(k)) * |y - x|)))))]
Latex:
Latex:
1. I : Interval
2. f : I {}\mrightarrow{}\mBbbR{}
3. g : I {}\mrightarrow{}\mBbbR{}
4. \mforall{}x,y:\{t:\mBbbR{}| t \mmember{} I\} . ((x = y) {}\mRightarrow{} (g[x] = g[y]))
5. d(f[x])/dx = \mlambda{}x.g[x] on I
6. k : \mBbbN{}\msupplus{}
7. n : \{n:\mBbbN{}\msupplus{}| icompact(i-approx(I;n)) \mwedge{} iproper(i-approx(I;n))\}
8. \mforall{}a,b:\{x:\mBbbR{}| x \mmember{} i-approx(I;n)\} . ((a = b) {}\mRightarrow{} (f[a] = f[b]))
9. i-approx(I;n) \msubseteq{} I
10. \mforall{}x:\mBbbR{}. ((x \mmember{} I) {}\mRightarrow{} f[x] \mneq{} r0)
11. \mexists{}c:\mBbbR{} [((r0 < c) \mwedge{} (\mforall{}x:\mBbbR{}. ((x \mmember{} i-approx(I;n)) {}\mRightarrow{} (c \mleq{} |f[x]|))))]
12. (r1/f[x]) continuous for x \mmember{} i-approx(I;n)
13. g[x] continuous for x \mmember{} i-approx(I;n)
14. \mforall{}x:\mBbbR{}. ((x \mmember{} i-approx(I;n)) {}\mRightarrow{} f[x] \mneq{} r0)
\mvdash{} \mexists{}del:\mBbbR{} [((r0 < del)
\mwedge{} (\mforall{}x,y:\mBbbR{}.
((x \mmember{} i-approx(I;n))
{}\mRightarrow{} (y \mmember{} i-approx(I;n))
{}\mRightarrow{} (|y - x| \mleq{} del)
{}\mRightarrow{} (|(r1/f[y]) - (r1/f[x]) - (-(g[x])/f[x] * f[x]) * (y - x)| \mleq{} ((r1/r(k))
* |y - x|)))))]
By
Latex:
Assert \mkleeneopen{}\mexists{}M:\mBbbN{}\msupplus{}. \mforall{}x:\mBbbR{}. ((x \mmember{} i-approx(I;n)) {}\mRightarrow{} ((|g[x]| \mleq{} r(M)) \mwedge{} (|(r1/f[x])| \mleq{} r(M))))\mkleeneclose{}\mcdot{}
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