Multi Statement Table-valued UDF Without Declaring Columns?

Hey
I have created a multi-statement
table valued function

alter 
function
fn_x(@x int)
returns
@tbl table
(

          position int identity primary key,
          i
int
)
as
begin
         
insert
into
@tbl values
(@x)
          insert
into
@tbl values
(@x)
          insert
into
@tbl values
(@x)
          insert
into
@tbl values
(@x)
          return
end
 



Is it possible skipping the
definition of the table columns (the light blue
part)?
I need to return a different
structure based on a parameter.
Dropping those lines throws an
error "incorrect syntax near 'as'"
 
The other solution is declaring
each udf separately as one statement udf.Thanks