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10.4. The system prelude and task list
10.4.1. The system prelude
The representation of the system-prelude is obtained
from the following form, to which may be added further forms not defined
in this Report. {The syntax of program-texts ensures that a declaration
contained in the
system-prelude may not contradict any declaration
contained in the
standard-prelude. It is intended that the further
forms should contain declarations that are needed for the correct operation
of any system-tasks that may be added (by the implementer, as provided
in 10.1.2.d
).}
a) SEMA {?}gremlins =(SEMA s; {F}f OF s := PRIM INT := 0; s);
10.4.2. The system task list
The representation of the {first} constituent system-task
or the system-task-list is obtained from the following form. The
other system-tasks, if any, are not defined by this Report {but
may be defined by the implementer in order to account for the particular
features of his operating environment, especially in so far as they interact
with the running of particular-programs (see, e.g., 10.3.1.1.dd
)}
.
DO DOWN gremlins; undefined; UP bfileprotect OD
{The intention is that this call of undefined,
which is released by an UP gremlins whenever a book is closed,
may reorganize the chain of backfiles and the chain of locked backfiles,
such as by removing the book if it is not to be available for further opening,
or by inserting it into the chain of backfiles several times over if it
is to be permitted for several particular-programs to read it simultaneously.
Note that, when an UP gremlins is given, bfileprotect
is always down and remains so until such reorganization has taken place.}
{From ghoulies and ghosties and long-leggety
beasties and things that go bump in the night. Good Lord, deliver us! Ancient
Cornish litany}
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