| ⊦ prefixn(n, x0) ⊑ x1 ∧ n < # x0 → (# x1 < n ↔ false) |
⊦ prefixn(n, x) = (n ≤ # x ⊃ firstn(n, x);x)
[Concretesimprules((Csimpnamedseq(prefixn,,, ⊦ prefixn(n, x) = (n ≤ # x ⊃ firstn(n, x);x)) Csimpnamedseq(nat-basic2,,succ, ⊦ m +1 = m + 1) Csimpnamedseq(list-data,,l, ⊦ # x = 0 ↔ x = []) Csimpnamedforward(nat-basic1,,trans-1, ⊦ n < n0 ∧ n0 < n1 → n < n1) Csimpnamedforward(nat-basic1,,f, ⊦ m < n → n ≠ 0) Csimpnamedforward(nat-basic1,,lf, ⊦ m < n ∧ n < n0 → m +1 < n0) Csimpnamedseq(nat,,lels-03, ⊦ m < n → m ≤ n)))]