On the Kurosh rank of the intersection of subgroups in free products of groups

The Kurosh rank rK(H) of a subgroup H of a free product of groups Gα, α∈I, is defined accordingly to the classic Kurosh subgroup theorem as the number of free factors of H. We prove that if H1, H2 are subgroups of and H1, H2 have finite Kurosh rank, then , where , q∗ is the minimum of orders >2 of finite subgroups of groups Gα, α∈I, q∗:=∞ if there are no such subgroups, and if q∗=∞. In particular, if the factors Gα, α∈I, are torsion-free groups, then .