| ⊦ perm(ar, ar0) ∧ m < # ar ∧ n < # ar ∧ m ≠ n → (¬ perm(ar, ar0[n, ar0[m]][m, ar0[n]]) ↔ false) |
n < # ar, m < # ar, perm(ar, ar0) ⊦ m = n, perm(ar, ar0[n, ar0[m]][m, ar0[n]])
[Concretesimprules((Csimpnamedseq(nat-basic1,,f, ⊦ m < n → n ≠ 0) Csimpnamedforward(nat-basic1,,f, ⊦ m < n → n ≠ 0)))]