Numbers come in two breeds: standard, for reading in data and as parts
of equations. The latter are not permitted to have exponent,
whereas the former can. Thus the following is a legitimate standard
number: -14.06e-17.
Output is flushed to output files (and to the history file and the log file, if these are in use) at the end of each command. If a crash happens during a command, any output from that command will be lost.
Errors are automatically echoed to screen - unless the job is a pure batch job, i.e. when channel 0 (the keyboard and screen) has never been referenced (read from or written to).