An inequality for strongly resolvable designs
Consider a (\(\nu\),k,\(\lambda)\)-design with a strong resolution having parameters \(\mu_ i\) (the inner constant, i.e. the intersection number of blocks in the same class of the resolution) and \(\rho\) (the number of blocks of a given class through a given point). The authors prove the inequality \(\lambda \geq \mu_ i+\rho\) provided that the given design is not symmetric; this result was conjectured by \textit{A. Beutelspacher} and \textit{U. Porta} [J. Geom. 19, 115-129 (1982; Zbl 0508.05015)]. The authors also give several equivalent inequalities, e.g. \(r\geq k+\rho\), and exhibit examples where one has equality.
scientific article; zbMATH DE number 3959437