| n0 < # kar, n0 ≤ # kar → (ki ∈ keyset(kar, n0) ↔ (∃ m. m < n0 ∧ ki = kar[m])) ⊦ ki = kar[n0] ∨ ki ∈ keyset(kar, n0) ↔ (∃ m. ¬ n0 < m ∧ ki = kar[m]) |
ki ∈ keyset(kar, n0) ↔ (∃ m. m < n0 ∧ ki = kar[m]), n0 < # kar ⊦ ki = kar[n0] ∨ ki ∈ keyset(kar, n0) ↔ (∃ m. ¬ n0 < m ∧ ki = kar[m])
Used simplifier rules: ⊦ m < n → m ≤ n; (s)