Is it permissible for a Muslim to offer condolences to a non-Muslim, visit their grave, and participate in their burial?

It is permissible to offer condolences to a disbeliever for their deceased, by saying: "May Allah compensate you." However, it is not permissible to follow their funeral procession or participate in their burial, due to the veneration involved, unless there is a concern that the body will be lost, in which case it is permissible to bury it. There is no harm for a wife or anyone else to visit her disbelieving family members to offer condolences, but it is not permissible to enter the church with them on the day of burial or to participate in the burial and follow the funeral procession.