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Proof step 1 from proof convergesto-neg-convergesto (conclusion) (back to tree)

⊦ converges(f, r) ↔ converges(λ n. ~ f(n), ~ r)

System applied rule normalize

And obtained the following new goals

Rule argument

Additional information

Proof step 2 from proof convergesto-neg-convergesto (previous step) (back to tree)

¬(converges(f, r) ↔ converges(λ n. ~ f(n), ~ r)) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name: convergesto-def, seq: ⊦ converges(f, r) ↔ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(f(n0) - r) < ε)), subst:[f, r] → [f, r], <all paths>

Additional information

Used terms: f, r

Proof step 3 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ converges(f, r) ↔ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(f(n0) - r) < ε))

Lemma convergesto-def

Proof step 4 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(f(n0) - r) < ε)) ↔ converges(λ n. ~ f(n), ~ r)

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ r - r0 = r + ~ r0; (s) ⊦ n ≥ m ↔ m ≤ n; (s) ⊦ r > r0 ↔ r0 < r; (s)

Proof step 5 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ (∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε)) ↔ converges(λ n. ~ f(n), ~ r)

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name: convergesto-def, seq: ⊦ converges(f, r) ↔ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(f(n0) - r) < ε)), subst:[f, r] → [λ n. ~ f(n), ~ r], <all paths>

Additional information

Used terms: λ n. ~ f(n), ~ r

Proof step 6 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ converges(f, r) ↔ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(f(n0) - r) < ε))

Lemma convergesto-def

Proof step 7 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ (∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε)) ↔ (∀ ε. ε > 0.r → (∃ n. ∀ n0. n0 ≥ n → abs(~ f(n0) - ~ r) < ε))

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ~ ~ r = r; (s) ⊦ r - r0 = r + ~ r0; (s) ⊦ n ≥ m ↔ m ≤ n; (s) ⊦ r > r0 ↔ r0 < r; (s)

Proof step 8 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ (∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε)) ↔ (∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε))

User applied rule case distinction

And obtained the following new goals

Rule argument

pos: right 1

Additional information

Proof step 9 from proof convergesto-neg-convergesto (previous step) (back to tree)

∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε) ⊦ ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε)

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 10 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε) ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε

User applied rule all left

And obtained the following new goals

Rule argument

pos: left 2 terms: ε abort: F discard: T computed: T

Additional information

Used terms: ε

Proof step 11 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε) ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 12 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε

User applied rule exists right

And obtained the following new goals

Rule argument

pos: right 1 terms: n abort: F discard: T computed: T

Additional information

Used terms: n

Proof step 13 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε ⊦ ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: add-comm: ⊦ r + r0 = r0 + r; from specification real-basic add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic ⊦ r + 0.r = r; (s) ⊦ r + ~ r0 = r1 ↔ r = r1 + r0; (s) ⊦ 0.r < abs(r) ↔ r ≠ 0.r; (s) forward-le: ⊦ r ≤ r0 ∧ 0.r < r → 0.r < r0; (forward) from specification real-abs ⊦ r < r0 ↔ ¬ r0 ≤ r; (ss)

Proof step 14 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), 0.r < ε, ε ≤ abs(~ f(n0) + r), n ≤ n0, ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε ⊦

User applied rule all left

And obtained the following new goals

Rule argument

pos: left 5 terms: n0 abort: F discard: T computed: T

Additional information

Used terms: n0

Proof step 15 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), 0.r < ε, n ≤ n0, ε ≤ abs(~ f(n0) + r), n ≤ n0 → abs(f(n0) + ~ r) < ε ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: forward-lsle: ⊦ r < r0 ∧ r0 ≤ r1 → r < r1; (forward) from specification real-abs

Proof step 16 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), 0.r < ε, abs(f(n0) + ~ r) < ε, abs(f(n0) + ~ r) < abs(~ f(n0) + r), ε ≤ abs(~ f(n0) + r), n ≤ n0 ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: real-abs, name: Abs-pos, seq: ⊦ ¬ r < 0.r → abs(r) = r, subst:[r] → [f(n0) + ~ r], <all paths>

Additional information

Used terms: f(n0) + ~ r

Proof step 17 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ ¬ r < 0.r → abs(r) = r

A spec-lemma

Proof step 18 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), f(n0) + ~ r < 0.r, abs(f(n0) + ~ r) < abs(~ f(n0) + r), abs(f(n0) + ~ r) < ε, 0.r < ε, n ≤ n0, ε ≤ abs(~ f(n0) + r) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: add-comm: ⊦ r + r0 = r0 + r; from specification real-basic add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic ⊦ r < r0 + ~ r1 ↔ r + r1 < r0; (s) ⊦ r - r0 = r + ~ r0; (s) ⊦ r0 < r → abs(r + ~ r0) = r - r0; (s) ⊦ r ≤ r0 + ~ r1 ↔ r + r1 ≤ r0; (s) ⊦ r + ~ r0 < 0.r ↔ r < r0; (s)

Proof step 19 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), f(n0) < r, 0.r < ε, abs(f(n0) + ~ r) < ε, abs(f(n0) + ~ r) + f(n0) < r, ε + f(n0) ≤ r, n ≤ n0 ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: real-abs, name: Abs-neg, seq: ⊦ r < 0.r → abs(r) = ~ r, subst:[r] → [f(n0) + ~ r], <all paths>

Additional information

Used simplifier rules: ⊦ r + ~ r0 < 0.r ↔ r < r0; (s) ⊦ ~(r + r0) = ~ r + ~ r0; (s) ⊦ ~ ~ r = r; (s) ⊦ r + ~ r0 < r1 ↔ r < r0 + r1; (s) ⊦ r ≤ r0 → ¬ r0 < r; (s) add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic add-comm: ⊦ r + r0 = r0 + r; from specification real-basic ⊦ ¬ r < 0.r → abs(r) = r; (s) ⊦ r + r = 2.r * r; (s) ⊦ i > 0 → (i.r * r0 < i.r * r2 ↔ r0 < r2); (s) mult-ass: ⊦ (r * r0) * r1 = r * r0 * r1; from specification real-multdiv commutativity: ⊦ r * r0 = r0 * r; from specification real-multdiv ⊦ r < r0 ↔ ¬ r0 ≤ r; (ss) ⊦ r < r0 → (r0 ≤ r ↔ false); (as) Used terms: f(n0) + ~ r

Proof step 20 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ r < 0.r → abs(r) = ~ r

A spec-lemma

Proof step 21 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), f(n0) + ~ r < abs(~ f(n0) + r), f(n0) + ~ r < ε, 0.r < ε, n ≤ n0, ε ≤ abs(~ f(n0) + r), ¬ f(n0) + ~ r < 0.r ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: add-comm: ⊦ r + r0 = r0 + r; from specification real-basic add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic ⊦ 0.r < r → r0 < r0 + r; (s) ⊦ r + 0.r = r; (s) ⊦ r + ~ r0 = r1 ↔ r = r1 + r0; (s) ⊦ 0.r < abs(r) ↔ r ≠ 0.r; (s) ⊦ r < r + r0 ↔ 0.r < r0; (s) trans: ⊦ r < r0 ∧ r0 < r1 → r < r1; (forward) from specification real-basic ⊦ r ≠ r0 → (r ≤ r0 ↔ r < r0); (s) ⊦ r < r0 ↔ ¬ r0 ≤ r; (ss) ⊦ r + ~ r0 < 0.r ↔ r < r0; (s) ⊦ r + ~ r0 < r1 ↔ r < r0 + r1; (s)

Proof step 22 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), r < f(n0), f(n0) < r + abs(~ f(n0) + r), f(n0) < r + ε, 0.r < ε, n ≤ n0, ε ≤ abs(~ f(n0) + r) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: real-abs, name: Abs-pos, seq: ⊦ ¬ r < 0.r → abs(r) = r, subst:[r] → [~ f(n0) + r], <all paths>

Additional information

Used simplifier rules: ⊦ r ≤ r0 + ~ r1 ↔ r + r1 ≤ r0; (s) ⊦ r < r0 + ~ r1 ↔ r + r1 < r0; (s) ⊦ r + r = 2.r * r; (s) ⊦ i > 0 → (i.r * r0 < i.r * r2 ↔ r0 < r2); (s) ⊦ r < r0 → ¬ r0 < r; (s) mult-ass: ⊦ (r * r0) * r1 = r * r0 * r1; from specification real-multdiv commutativity: ⊦ r * r0 = r0 * r; from specification real-multdiv add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic add-comm: ⊦ r + r0 = r0 + r; from specification real-basic Used terms: ~ f(n0) + r

Proof step 23 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ ¬ r < 0.r → abs(r) = r

A spec-lemma

Proof step 24 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), ~ f(n0) + r < 0.r, 0.r < ε, f(n0) < r + ε, f(n0) < r + abs(~ f(n0) + r), r < f(n0), ε ≤ abs(~ f(n0) + r), n ≤ n0 ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: add-comm: ⊦ r + r0 = r0 + r; from specification real-basic add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic ⊦ r + ~ r0 < 0.r ↔ r < r0; (s)

Proof step 25 from proof convergesto-neg-convergesto (previous step) (back to tree)

r ≠ f(n0), f(n0) < r + abs(~ f(n0) + r), f(n0) < r + ε, 0.r < ε, r < f(n0), n ≤ n0, ε ≤ abs(~ f(n0) + r) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: real-abs, name: Abs-neg, seq: ⊦ r < 0.r → abs(r) = ~ r, subst:[r] → [~ f(n0) + r], <all paths>

Additional information

Used simplifier rules: ⊦ ~(r + r0) = ~ r + ~ r0; (s) ⊦ ~ ~ r = r; (s) ⊦ r ≤ r0 + ~ r1 ↔ r + r1 ≤ r0; (s) ⊦ r < r0 → (r0 ≤ r ↔ false); (as) add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic add-comm: ⊦ r + r0 = r0 + r; from specification real-basic ⊦ ¬ r < 0.r → abs(r) = r; (s) ⊦ r < r0 + ~ r1 ↔ r + r1 < r0; (s) ⊦ r + r = 2.r * r; (s) ⊦ i > 0 → (i.r * r0 < i.r * r2 ↔ r0 < r2); (s) ⊦ r < r0 → ¬ r0 < r; (s) mult-ass: ⊦ (r * r0) * r1 = r * r0 * r1; from specification real-multdiv commutativity: ⊦ r * r0 = r0 * r; from specification real-multdiv Used terms: ~ f(n0) + r

Proof step 26 from proof convergesto-neg-convergesto (previous step) (back to tree)

⊦ r < 0.r → abs(r) = ~ r

A spec-lemma

Proof step 27 from proof convergesto-neg-convergesto (previous step) (back to tree)

∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦ ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε)

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 28 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε

User applied rule apply proof lemma

And obtained the following new goals

Rule argument

path: 1, 2, 1, 2, 1, 1, 1 subst: [ε, f, r] → [ε, λ n. ~ f(n), ~ r]

Additional information

Proof step 29 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε) ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε

Proof step 10 used as proof-lemma

Proof step 30 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦ ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + ~ ~ r) < ε), ∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ~ ~ r = r; (s)

Proof step 31 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε0, 0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε, ∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε0

Heuristic quantifier closing applied rule all left

And closed the goal!

Rule argument

pos: left 3 terms: ε0

Additional information

Used terms: ε0

Proof step 32 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε), ∃ n. ∀ n0. n ≤ n0 → abs(~ ~ f(n0) + ~ r) < ε ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ~ ~ r = r; (s)

Proof step 33 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε), ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε ⊦ ∃ n. ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε

User applied rule exists right

And obtained the following new goals

Rule argument

pos: right 1 terms: n abort: F discard: T computed: T

Additional information

Used terms: n

Proof step 34 from proof convergesto-neg-convergesto (previous step) (back to tree)

0.r < ε, ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦ ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: add-comm: ⊦ r + r0 = r0 + r; from specification real-basic add-assoc: ⊦ (r + r0) + r1 = r + r0 + r1; from specification real-basic ⊦ r + 0.r = r; (s) ⊦ r + ~ r0 = r1 ↔ r = r1 + r0; (s) ⊦ 0.r < abs(r) ↔ r ≠ 0.r; (s) forward-le: ⊦ r ≤ r0 ∧ 0.r < r → 0.r < r0; (forward) from specification real-abs ⊦ r < r0 ↔ ¬ r0 ≤ r; (ss)

Proof step 35 from proof convergesto-neg-convergesto (previous step) (back to tree)

f(n0) ≠ r, 0.r < ε, ε ≤ abs(f(n0) + ~ r), n ≤ n0, ∀ n0. n ≤ n0 → abs(f(n0) + ~ r) < ε, ∀ ε. 0.r < ε → (∃ n. ∀ n0. n ≤ n0 → abs(~ f(n0) + r) < ε) ⊦

Heuristic quantifier closing applied rule all left

And closed the goal!

Rule argument

pos: left 5 terms: n0

Additional information

Used simplifier rules: ⊦ r ≤ r0 → ¬ r0 < r; (s) Used terms: n0

Proof Tree for convergesto-neg-convergesto (View conclusion)

The following image shows the proof tree of sequent calculus. The proved goal is at the bottom. You can click on the nodes to view additional rules. See here for details on colors in a proof tree.

the proof tree