Logical languages are meant to allow (or enforce) unambiguous statements. They are typically based on predicate logic but can also be based on any system of formal logic. The two best-known logical languages are the predicate languages Loglan and its successor Lojban. They both aim to eliminate syntactical ambiguity and reduce semantic ambiguity to a minimum. In particular, the grammar of Lojban is carefully engineered to express such predicate logic in an unambiguous manner. Toaq and Eberban are also logical languages.