source: [lemma=thus] [□=□] □ □
destination: [lemma=thus] [word=□] □ □
spec: The compressor is thus always reponsible to figure out what is the most suitable response to a negative acknowledgement , using the confidence it has in the state of the decompressor context , when selecting the type of compressed header it will use when compressing a header . It can help advocates determine if their needs are being addressed in the planning process and whether plan components are being implemented .