NSPredicate *predicate1 = [NSPredicate predicateWithFormat:
@"valid_date == <NSDate object>"];

NSPredicate *predicate2 = [NSPredicate predicateWithFormat:
@"ANY card_user like currentUser"];

NSSet *setOfCreditCards = currentUser.creditcards;
NSPredicate *filter = [NSPredicate predicateWithFormat: @"valid_date == %@", date];
NSSet *cardsWithValidDates = [setOfCreditCards filteredSetUsingPredicate:filter];

NSPredicate* predicate = [NSPredicate predicateWithFormat:@"person == %@ AND valid_date == %@", currentUser, valid_date];