Before revision:  However, since the knowledge in logical databases in practice always is incomplete  , forward reasoning of automated reasoning systems alone does not suffice to derive answers to questions because, instead of complete proofs, often only partial positive knowledge can be derived . In consequence, negative information from negated expressions does not help in this context, because only negative knowledge can be derived from this. Therefore ,  we aim at reducing syntactic negation, strictly speaking, the negated event or property , to its inverse.
After revision:  However, since the knowledge in logical databases in practice always is incomplete , forward reasoning of automated reasoning systems alone does not suffice to derive answers to questions because, instead of complete proofs, often only partial positive knowledge can be derived , we aim at reducing syntactic negation, strictly speaking, the negated event or property , to its inverse.