One way to kill a Unisys mainframe COBOL application is to explicitly cause a divide by zero error. Doing this will cause a fatal program error.
Why would someone want to explicitly cause this error:
- Database or other key data is not on file
- Edits on data find bad information
- Date checks on a file show that the file is too old
Of course, sometimes the error happens when it is unwanted. In cases like that, a programmer usually grumbles something about "bad data from the client" or the like, and never blames his or her self.