Debugging commands

In debugging mode, the system displays a message when a predicate is entered (Call), exited (Exit), reentered (Redo) or has failed (Fail). After a predicate is entered or reentered, the system waits for a command from the user. A command is a single letter followed by a carriage-return or simply a carriage-return. The following commands are available:

• RET - This command causes the system to display a message at each step.
• c(reep) - the same as a carriage-return RET.
• l(eap) - causes the system to run in usual mode until a spy-point is reached.
• s(kip) - causes the system to run in usual mode until the predicate is finished (Exit or Fail).

• r(epeat creep) - causes the system to creep without asking for further commands from the user.
• a(bort) - causes the system to abort execution.
• h(elp) or ? - causes the system to display available commands and their meaning.