Semiuniform spaces, and seminorms, semimetrics, semiecarts in apo-semigroups. (English). In: Franklin, S. P., Frolík, Z. and Koutník, V. (eds.): General Topology and Its Relations to Modern Analysis and Algebra. Proceedings of the Kanpur topological conference, 1968. Academia Publishing House of the Czechoslovak Academy of Sciences, Praha, 1971. pp. [163]-171