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Proof step 1 from proof remtau-equiv (conclusion) (back to tree)

¬ finp(ext !(⌜af⌝ )) ⊦ ext !(⌜af⌝ ) = ext !(⌜af0⌝ ) ↔ (∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)))

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ finp(σ) ↔ ¬(∃ nf. ⌜nf⌝ = σ); (ss)

Proof step 2 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ) ⊦ ⌜ef⌝ = ext !(⌜af0⌝ ) ↔ (∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)))

User applied rule case distinction

And obtained the following new goals

Rule argument

pos: right 1

Additional information

Proof step 3 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ⌜ef⌝ = ext !(⌜af0⌝ ) ⊦ ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 4 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ) ⊦ ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

User applied rule apply lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name:to_of_remtau-remtau_of_to, seq:⊦ ¬ # α < ⌜n⌝ → (∃ m. ¬ # ext !(α) < ⌜m⌝ ∧ ext !(⌜α.take(n)⌝ ) = ⌜ext !(α).take(m)⌝ ), subst:[α, n, ext] → [⌜af⌝ , n, ext]; ['a, 'e] → ['a, 'e]

Additional information

Used terms: ⌜af⌝ , n, ext

Proof step 5 from proof remtau-equiv (previous step) (back to tree)

⊦ ¬ # α < ⌜n⌝ → (∃ m. ¬ # ext !(α) < ⌜m⌝ ∧ ext !(⌜α.take(n)⌝ ) = ⌜ext !(α).take(m)⌝ )

Lemma to_of_remtau-remtau_of_to

Proof step 6 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ⌜ef⌝ = ext !(⌜af0⌝ ), ¬ # ⌜af⌝ < ⌜n⌝ → (∃ m. ¬ # ext !(⌜af⌝ ) < ⌜m⌝ ∧ ext !(⌜⌜af⌝ .take(n)⌝ ) = ⌜ext !(⌜af⌝ ).take(m)⌝ ) ⊦ ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: finremtau-def: ⊦ ext !(⌜al⌝ ) = ⌜ext !(al)⌝ ; ⊦ ¬ ∞ < n∞; (s) ⊦ # ⌜nf⌝ = ∞; (s) ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ ⌜x⌝ = ⌜x0⌝ ↔ x = x0; (s)

Proof step 7 from proof remtau-equiv (previous step) (back to tree)

ext !(af.take(n)) = ef.take(m), ⌜ef⌝ = ext !(⌜af⌝ ), ⌜ef⌝ = ext !(⌜af0⌝ ) ⊦ ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

User applied rule apply lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name:remtau_of_to-to_of_rmtau, seq:⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m))), subst:[ext, α, n] → [ext, ⌜af0⌝ , m]; ['a, 'e] → ['a, 'e]

Additional information

Used terms: ext, ⌜af0⌝ , m

Proof step 8 from proof remtau-equiv (previous step) (back to tree)

⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m)))

Lemma remtau_of_to-to_of_rmtau

Proof step 9 from proof remtau-equiv (previous step) (back to tree)

ext !(af.take(n)) = ef.take(m), ⌜ef⌝ = ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ¬ # ext !(⌜af0⌝ ) < ⌜m⌝ → (∃ m0. ¬ # ⌜af0⌝ < ⌜m0⌝ ∧ ext !(⌜af0⌝ ).take(m) = ext !(⌜af0⌝ .take(m0))) ⊦ ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ ¬ ∞ < n∞; (s) ⊦ # ⌜nf⌝ = ∞; (s)

Proof step 10 from proof remtau-equiv (previous step) (back to tree)

ext !(af.take(n)) = ef.take(m), ef.take(m) = ext !(af0.take(m0)), ⌜ef⌝ = ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ) ⊦ ∃ m. ext !(af.take(n)) = ext !(af0.take(m))

User applied rule exists right

And closed the goal!

Rule argument

pos: right 1 terms: m0 abort: F discard: T computed: T

Additional information

Used terms: m0

Proof step 11 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ⌜ef⌝ ≠ ext !(⌜af0⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: stream, name: extensionality-to, seq:⊦ σ0 = σ1 ↔ # σ0 = # σ1 ∧ (∀ n. ¬ # σ0 < ⌜n⌝ → σ0.take(n) = σ1.take(n)), subst:[σ0, σ1] → [⌜ef⌝ , ext !(⌜af0⌝ )]; ['a] → ['e], <all paths>

Additional information

Used terms: ⌜ef⌝ , ext !(⌜af0⌝ )

Proof step 12 from proof remtau-equiv (previous step) (back to tree)

⊦ σ0 = σ1 ↔ # σ0 = # σ1 ∧ (∀ n. ¬ # σ0 < ⌜n⌝ → σ0.take(n) = σ1.take(n))

A spec-lemma

Proof step 13 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), # ⌜ef⌝ ≠ # ext !(⌜af0⌝ ) ∨ (∃ n. ¬(¬ # ⌜ef⌝ < ⌜n⌝ → ⌜ef⌝ .take(n) = ext !(⌜af0⌝ ).take(n))) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ ¬ ∞ < n∞; (s) ⊦ # ⌜nf⌝ = ∞; (s)

Proof step 14 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∞ ≠ # ext !(⌜af0⌝ ) ∨ ef.take(n) ≠ ext !(⌜af0⌝ ).take(n) ⊦

User applied rule cut formula

And obtained the following new goals

Rule argument

fma: ∞ ≠ # ext !(⌜af0⌝ )

Additional information

Used formulas: ∞ ≠ # ext !(⌜af0⌝ )

Proof step 15 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ∞ ≠ # ext !(⌜af0⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∞ ≠ # ext !(⌜af0⌝ ) ∨ ef.take(n) ≠ ext !(⌜af0⌝ ).take(n) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 16 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ∞ ≠ # ext !(⌜af0⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: nat-inf, name: notinf-fin, seq: ⊦ n∞ = ∞ ↔ ¬(∃ n. n∞ = ⌜n⌝ ), subst:[n∞] → [# ext !(⌜af0⌝ )], <all paths>

Additional information

Used terms: # ext !(⌜af0⌝ )

Proof step 17 from proof remtau-equiv (previous step) (back to tree)

⊦ n∞ = ∞ ↔ ¬(∃ n. n∞ = ⌜n⌝ )

A spec-lemma

Proof step 18 from proof remtau-equiv (previous step) (back to tree)

⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∃ n. # ext !(⌜af0⌝ ) = ⌜n⌝ ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 19 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name:remtau_of_to-to_of_rmtau, seq:⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m))), subst:[ext, α, n] → [ext, ⌜af⌝ , n + 1]; ['a, 'e] → ['a, 'e]

Additional information

Used terms: ext, ⌜af⌝ , n + 1

Proof step 20 from proof remtau-equiv (previous step) (back to tree)

⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m)))

Lemma remtau_of_to-to_of_rmtau

Proof step 21 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ⌜ef⌝ = ext !(⌜af⌝ ), ¬ # ext !(⌜af⌝ ) < ⌜n + 1⌝ → (∃ m. ¬ # ⌜af⌝ < ⌜m⌝ ∧ ext !(⌜af⌝ ).take(n + 1) = ext !(⌜af⌝ .take(m))), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ ⌜m⌝ < ∞; (s) ⊦ # ⌜nf⌝ = ∞; (s) ⊦ ¬ ∞ < n∞; (s) add-comm: ⊦ n∞1 + n∞2 = n∞2 + n∞1; from specification nat-inf add-assoc: ⊦ (n∞ + n∞1) + n∞2 = n∞ + n∞1 + n∞2; from specification nat-inf ⊦ # σ < ⌜n⌝ + ⌜1⌝ ↔ ¬ ⌜n⌝ < # σ; (s) c: ⊦ m + n = n + m; from specification nat-basic a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic ⊦ ⌜m + n⌝ = ⌜m⌝ + ⌜n⌝ ; (s)

Proof step 22 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ef.take(n + 1) = ext !(af.take(m)), ⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule all left

And obtained the following new goals

Rule argument

pos: left 4 terms: m abort: F discard: F computed: F

Additional information

Used terms: m

Proof step 23 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ef.take(n + 1) = ext !(af.take(m)), ⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∃ m0. ext !(af.take(m)) = ext !(af0.take(m0)) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 24 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ef.take(n + 1) = ext !(af0.take(m0)), ef.take(n + 1) = ext !(af.take(m)), ⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: stream, name: extensionality, seq: ⊦ σ0 = σ1 ↔ # σ0 = # σ1 ∧ (∀ n. ⌜n⌝ < # σ0 → σ0[n] = σ1[n]), subst:[σ0, σ1] → [⌜ef⌝ , ext !(⌜af⌝ )]; ['a] → ['e], <all paths>

Additional information

Used terms: ⌜ef⌝ , ext !(⌜af⌝ )

Proof step 25 from proof remtau-equiv (previous step) (back to tree)

⊦ σ0 = σ1 ↔ # σ0 = # σ1 ∧ (∀ n. ⌜n⌝ < # σ0 → σ0[n] = σ1[n])

A spec-lemma

Proof step 26 from proof remtau-equiv (previous step) (back to tree)

# ⌜ef⌝ = # ext !(⌜af⌝ ), # ext !(⌜af0⌝ ) = ⌜n⌝ , ef.take(n + 1) = ext !(af.take(m)), ef.take(n + 1) = ext !(af0.take(m0)), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∀ n. ⌜n⌝ < # ⌜ef⌝ → ⌜ef⌝ [n] = ext !(⌜af⌝ )[n] ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ [n] = nf(n); (s) ⊦ ⌜m⌝ < ∞; (s) ⊦ # ⌜nf⌝ = ∞; (s)

Proof step 27 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜af0⌝ ) = ⌜n⌝ , ef.take(n + 1) = ext !(af0.take(m0)), ef.take(n + 1) = ext !(af.take(m)), ∞ = # ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∀ n0. ef(n0) = ext !(⌜af⌝ )[n0] ⊦

User applied rule apply lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name:not-lessto, seq:¬ # α < ⌜n⌝ ⊦ ¬ # ext !(α) < # ⌜ext !(α.take(n))⌝ , subst:[α, n, ext] → [⌜af0⌝ , m0, ext]; ['a, 'e] → ['a, 'e]

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ # ⌜x⌝ = ⌜# x⌝ ; (s) ⊦ # nf.take(n) = n; (s) ⊦ ⌜m + n⌝ = ⌜m⌝ + ⌜n⌝ ; (s) a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic c: ⊦ m + n = n + m; from specification nat-basic ⊦ ⌜n⌝ < ⌜1⌝ + n∞ ↔ ¬ n∞ < ⌜n⌝ ; (s) ⊦ ⌜m⌝ < ⌜n⌝ ↔ m < n; (s) ⊦ ¬ n < n; (s) add-assoc: ⊦ (n∞ + n∞1) + n∞2 = n∞ + n∞1 + n∞2; from specification nat-inf add-comm: ⊦ n∞1 + n∞2 = n∞2 + n∞1; from specification nat-inf ⊦ # ⌜nf⌝ = ∞; (s) ⊦ ¬ ∞ < n∞; (s) Used terms: ⌜af0⌝ , m0, ext

Proof step 28 from proof remtau-equiv (previous step) (back to tree)

¬ # α < ⌜n⌝ ⊦ ¬ # ext !(α) < # ⌜ext !(α.take(n))⌝

Lemma not-lessto

Proof step 29 from proof remtau-equiv (previous step) (back to tree)

∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∞ ≠ # ext !(⌜af0⌝ ) ∨ ef.take(n) ≠ ext !(⌜af0⌝ ).take(n) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 30 from proof remtau-equiv (previous step) (back to tree)

∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply lemma

And obtained the following new goals

Rule argument

spec: <toplevel>, name:remtau_of_to-to_of_rmtau, seq:⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m))), subst:[ext, α, n] → [ext, ⌜af⌝ , n]; ['a, 'e] → ['a, 'e]

Additional information

Used terms: ext, ⌜af⌝ , n

Proof step 31 from proof remtau-equiv (previous step) (back to tree)

⊦ ¬ # ext !(α) < ⌜n⌝ → (∃ m. ¬ # α < ⌜m⌝ ∧ ext !(α).take(n) = ext !(α.take(m)))

Lemma remtau_of_to-to_of_rmtau

Proof step 32 from proof remtau-equiv (previous step) (back to tree)

∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ¬ # ext !(⌜af⌝ ) < ⌜n⌝ → (∃ m. ¬ # ⌜af⌝ < ⌜m⌝ ∧ ext !(⌜af⌝ ).take(n) = ext !(⌜af⌝ .take(m))), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: ⊦ ⌜nf⌝ .take(n) = nf.take(n); (s) ⊦ ¬ ∞ < n∞; (s) ⊦ # ⌜nf⌝ = ∞; (s)

Proof step 33 from proof remtau-equiv (previous step) (back to tree)

ef.take(n) = ext !(af.take(m)), ∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule all left

And obtained the following new goals

Rule argument

pos: left 5 terms: m abort: F discard: F computed: F

Additional information

Used terms: m

Proof step 34 from proof remtau-equiv (previous step) (back to tree)

ef.take(n) = ext !(af.take(m)), ∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)), ∃ m0. ext !(af.take(m)) = ext !(af0.take(m0)) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Proof step 35 from proof remtau-equiv (previous step) (back to tree)

ef.take(n) = ext !(af0.take(m0)), ef.take(n) = ext !(af.take(m)), ∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

User applied rule apply elim lemma

And obtained the following new goals

Rule argument

spec: stream, name:elim-fromto-inf, seq: ⊦ x0 = nf.take(n) ∧ nf0 = nf.drop(n) ↔ nf = (⌜x0⌝ + ⌜nf0⌝ ).f ∧ # x0 = n, subst:[nf, n, x0, nf0] → [af0, m0, al, nf0]; ['a] → ['a]

Additional information

Used simplifier rules: ⊦ x0 = nf.take(n) ∧ nf0 = nf.drop(n) ↔ nf = (⌜x0⌝ + ⌜nf0⌝ ).f ∧ # x0 = n; (elim) Used terms: af0, m0, al, nf0

Proof step 36 from proof remtau-equiv (previous step) (back to tree)

# al = m0, ef.take(n) = ext !(af.take(m)), ef.take(n) = ext !(al), af0 = (⌜al⌝ + ⌜nf0⌝ ).f, ∞ = # ext !(⌜af0⌝ ), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ ext !(⌜af0⌝ ).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !(af0.take(m)) ⊦

Heuristic simplifier applied rule simplifier

And obtained the following new goals

Rule argument

Additional information

Used simplifier rules: remtau-append: ⊦ ext !(⌜al⌝ + α2) = ⌜ext !(al)⌝ + ext !(α2); append-assoc: ⊦ (σ + σ1) + σ2 = σ + σ1 + σ2; from specification stream ⊦ ⌜(⌜x⌝ + ⌜nf⌝ ).f⌝ = ⌜x⌝ + ⌜nf⌝ ; (s) add-comm: ⊦ n∞1 + n∞2 = n∞2 + n∞1; from specification nat-inf add-assoc: ⊦ (n∞ + n∞1) + n∞2 = n∞ + n∞1 + n∞2; from specification nat-inf ⊦ ⌜m⌝ + n∞ = ∞ ↔ n∞ = ∞; (s) ⊦ # ⌜x⌝ = ⌜# x⌝ ; (s) ⊦ #(σ + σ1) = # σ + # σ1; (s)

Proof step 37 from proof remtau-equiv (previous step) (back to tree)

# ext !(⌜nf0⌝ ) = ∞, ef.take(n) = ext !(al), ef.take(n) = ext !(af.take(m)), ⌜ef⌝ = ext !(⌜af⌝ ), ef.take(n) ≠ (⌜ef.take(n)⌝ + ext !(⌜nf0⌝ )).take(n), ∀ n. ∃ m. ext !(af.take(n)) = ext !((⌜al⌝ + ⌜nf0⌝ ).f.take(m)) ⊦

User applied rule apply rewrite lemma

And obtained the following new goals

Rule argument

spec: stream, name: append-gr-to, seq: ⊦ # σ < ⌜n⌝ → (σ + σ0).take(n) = σ.l + σ0.take(n - # σ.l), subst:[σ, σ0, n] → [⌜ef.take(n)⌝ , ext !(⌜nf0⌝ ), n]; ['a] → ['e], <all paths>

Additional information

Used simplifier rules: ⊦ ⌜x⌝ .l = x; (s) ⊦ # nf.take(n) = n; (s) ⊦ m - m = 0; (s) ⊦ σ.take(0) = []; (s) ⊦ x + [] = x; (s) a: ⊦ (x + y) + z = x + y + z; from specification list ⊦ ¬ # σ < ⌜n⌝ → (σ + σ0).take(n) = σ.take(n); (s) ⊦ ⌜x⌝ .take(n) = x.take(n); (s) ⊦ nf.take(n).take(n) = nf.take(n); (s) append-assoc: ⊦ (σ + σ1) + σ2 = σ + σ1 + σ2; from specification stream Used terms: ⌜ef.take(n)⌝ , ext !(⌜nf0⌝ ), n

Proof step 38 from proof remtau-equiv (previous step) (back to tree)

⊦ # σ < ⌜n⌝ → (σ + σ0).take(n) = σ.l + σ0.take(n - # σ.l)

A spec-lemma

Proof Tree for remtau-equiv (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