Let E be a Banach lattice,
![](//static-cambridge-org.ezproxyberklee.flo.org/content/id/urn%3Acambridge.org%3Aid%3Aarticle%3AS0008439500061968/resource/name/S0008439500061968_eqn1.gif?pub-status=live)
where x1, …, xn ∊ E. We study properties of constants
![](//static-cambridge-org.ezproxyberklee.flo.org/content/id/urn%3Acambridge.org%3Aid%3Aarticle%3AS0008439500061968/resource/name/S0008439500061968_eqn2.gif?pub-status=live)
A characterization of AM-spaces is obtained which generalizes the result of Abramocič, Positselskiĭ, Yanovskii. Asymptotic estimates of φp for some classical finite dimensional lattices are given.