51.   Attempting to reserve a package module name which already exists.

52.   Invalid module names have been supplied to PI.

53.   Please supply valid module names which are known to LIFESPAN.

54.   The user has attempted to reserve a module name which is already known to LIFESPAN.

55.   The module name specified is unknown to LIFESPAN.

56.   A module name has been supplied to PI routine Read--From--Package which is not contained in the package.

57.   Repeat supplying valid module names.

58.   The user has supplied duplicate module names in the list supplied.

59.   Duplicate module names are not permitted and so you should repeat supplying a module name once only.

60.   You have tried to specify zero modules in the list of modules names to be reserved.