- File Trimmers:
  - File trimmers allow only a portion of a file to be read in.
  - When a file trimmer is used the file looks (to the primitive) as if the file has been "trimmed" to a smaller size. The "trimming" is done internal to the Midas framework without modifying the file.
  - File trimmers are specified by appending them to the end of a file name but before any qualifiers. For example:

        myfile.prm(<start>:<end>)

    In the above example `<start>` is the start position in the file and `<end>` is the end position in the file.
    - The start/end position can be one of the following:

      blank | Use the actual start/end of the file. | `myfile.prm(:<end>) myfile.prm(<start>:)`
      N | The absolute index (N) into the file. | `myfile.prm(N:<end>) myfile.prm(<start>:N)`
      -N | Start/end N elements before the end of the file. | `myfile.prm(-N:<end>) myfile.prm(<start>:-N)`
      ~N | Start/end at abscissa value N. | `myfile.prm(~N:<end>) myfile.prm(<start>:~N)`

  - Qualifiers and trimmers can be used at the same time, with trimmers followed by qualifiers. For example:

        X-Midas:   myfile.prm(10:51)(AUX=0)
        NeXtMidas: myfile.prm(9:50){AUX=CWD}

  - Some details of this will vary between Midas frameworks (especially 0-based vs 1-based indexing into a file).

Don't Make This Mistake:
Note: Trimmers must be defined first, then qualifiers.