 A third problem is that there can be regularity without causation. The cry of the cock precedes the rise of the sun and the two events are regularly associated. And yet the cry of the cock is not a cause of the sunrise. A special case of this problem arises from joint effects of a common cause. Suppose an instantiation \(c\) of \(C\) is a common cause of the instantiations \(a\) of \(A\) and \(b\) of \(B\), where the token event \(a\) precedes the token event \(b\) in time (see  Figure 1).  Further suppose \(C\) is instantiated whenever \(A\) is. That is, whenever a token event of type \(A\) occurs, a token event of type \(C\) occurs. Then there is a regular connection between \(A\) and \(B\), which we normally do not count as a causal relation. This problem remains a central challenge for regularity theories to date.