What we propose here is to reduce the size of Galois lattices still conserving their formal structure and exhaustivity. For that purpose we use a preliminary partition of the instance set, representing the association of a “type” to each instance. By redefining the notion of
of a term in order to cope, to a certain degree (denoted as
), with this partition, we define a particular family of Galois lattices denoted as
Alpha Galois lattices
. We also discuss the related implication rules defined as inclusion of such
-extents and show that Iceberg concept lattices are Alpha Galois lattices where the partition is reduced to one single class.