Presenting Inequations in Mathematical Proofs

Logical systems, such as deductive planning approaches and formal methods in software verification, increasingly make use of machine generated proofs, and the size of these is growing continuously. Their presentation, however, is often inadequate in large portions, because the internal proof structures differ significantly from presentation styles adequate for humans. Addressing improvements in a specific and frequently occurring aspect of proof presentation, this paper describes an approach to building chains of inequations and presenting them in a compact notation format. The methods used comprise restructuring techniques, the omission of redundant information motivated by the addressee's inferential capabilities, and the skillful use of a compact notation format. Our approach constitutes an important contribution to presenting mathematical proofs in a natural and human-oriented way.