.. productionlist::
SimpleValue: "(" `DagArg` `DagArgList` ")"
DagArgList: `DagArg` ("," `DagArg`)*
- DagArg: `Value` [":" `TokVarName`]
+ DagArg: `Value` [":" `TokVarName`] | `TokVarName`
The initial :token:`DagArg` is called the "operator" of the dag.