[Imprint][Data Privacy Statement][E-Mail]

View long theorem info. View the proof. Back to main index. View the specification. View theorem base summary, View theorem base listing, the used properties by spec, the dependency list, the symbol table,

Proof step 5 from proof get-firstn (previous step)

n < m, n ≤ # x0, m ≤ 1 + # x0, ∀ n, m. n < m ∧ n < # x0 ∧ m ≤ # x0 → firstn(m, x0)[n] = x0[n] ∨ x0 = [] ⊦ firstn(m, a ' + x0)[n] = (a ' + x0)[n]

Heuristic cut applied rule cut formula

And obtained the following new goals

Proof step 6:
n < m, m ≤ 1 + # x0, n ≤ # x0, ∀ n, m. n < m ∧ n < # x0 ∧ m ≤ # x0 → firstn(m, x0)[n] = x0[n] ∨ x0 = [] ⊦ firstn(m, a ' + x0)[n] = (a ' + x0)[n], x0 = []

Rule argument

fma: x0 = []

Additional information

Used simplifier rules: one-03: ⊦ a '[0] = a;%first-num: n ≠ 0 ⊦ firstn((* n), x) = x.head ' + firstn(n -1, x.tail);%firstN-zero: ⊦ firstn(0, x) = [];% ⊦ x + [] = x; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ # [] = 0; (s)% ⊦ m ≤ 0 ↔ m = 0; (s)%lf-02: ⊦ m < n ∧ m = n0 → n0 < n; (forward) from specification nat-basic%fle: ⊦ m < n ∧ n ≤ n0 → m < n0; (forward) from specification nat% ⊦ 0 < n ↔ n ≠ 0; (s)% ⊦ m < n → n ≠ 0; (s)% ⊦ m ≠ 0 → (m ≤ 1 ↔ m = 1); (s)% ⊦ a '.head = a; (s)% ⊦ a '.tail = []; (s) Used formulas: x0 = []