**
COMMAND SEQUENCES
     There are two main ways in which files containing TRIPOS commands
can be executed.  Either the C or the T command can be used.  If the C
command is used the file is processed in two passes.  The first is
responsible for the substitution of parameters and dealing with lines
beginning with the character "." (use HELP C COMMAND for further
information here).  The second pass is identical to the effect of the
T command - the file is executed as if it contained characters typed in
at the terminal (use HELP T COMMAND for information about the T command).
     There are a certain number of TRIPOS commands the major use of which
is within such command sequences:
        IF <args> ; <commands>     - conditionally executes <commands>
        SKIP <label>               - skips forewards to the label <label>
        LAB <label>                - indicates a label in the sequence
        QUIT <rc>                  - stops processing and returns <rc>
        FAILAT <rc>                - sets the return code at which the
                                     command sequence will abend
     For information about any of these commands use HELP COMMAND <command>.


