multiple idocs to multiline idoc.

I am actually working on an Idoc to edi scenario where i have two mappings:

N:1 mapping:- Multiple idocs to a single multiline idoc.

1:1 Mapping:- multiline idoc to EDI.

Now for this, all structures are imported; meaning there is no datatypes and message types to be defined.

Kindly explain a similar scenario if there is ??