| prefixn(n + 1, x0) = prefixn(n + 1, x1) ⊦ prefixn(n, x0) = prefixn(n, x1) |
prefixn(n + 1, []) = prefixn(n + 1, x1) ⊦ prefixn(n, []) = prefixn(n, x1)
prefixn(n + 1, a + x) = prefixn(n + 1, x1), ∀ n, x1. prefixn(n + 1, x) = prefixn(n + 1, x1) → prefixn(n, x) = prefixn(n, x1) ⊦ prefixn(n, a + x) = prefixn(n, x1)
Used simplifier rules: list freely generated by [], +;;