
A specification of the relationship between a concrete syntax and an
abstract syntax (@pxref{Relating,,,specs}) requires exactly one file of
type @code{con} to define the concrete syntax and one or more additional
files to relate it to the abstract syntax.
There are two ways to specify the relationship:

@itemize @bullet
@item
With exactly one file of type @code{abs} and exactly one file of type
@code{rel}

@item
With exactly one file of type @code{sym} and/or exactly one file of type
@code{cull}
@end itemize

Your specification consists of the following set of files:

