Multiple source modules
The assembler can assemble more than one source module in a single
input stream, if the BATCH option is specified. For more information
about the BATCH option, see the section BATCH
in the HLASM Programmer's Guide.
An input stream
may contain one or more “source
modules”, and may also consist of one or more data sets if the
host operating system supports data set or file concatenation. A source
module
is a single assembly.