Once the target state is selected, one or more states may be specified as the ``aspiring pre-images'' of the target state. These will be added to the target state if learning, or detached if forgetting. Alternatively the states may just be just highlighted.
The set of states may be an arbitrary list or a range of decimal equivalents (if n<=32), or may be based on Hamming distance, parity, or the previous list may be repeated. The following lower left prompt is presented,
pre-images: as before-b parity-p range-r hamm-h1/2 number-(default 1): (``range-r`` if n<=32)
Enter a number to specify the size of an arbitrary list of aspiring pre-images, or make alternative selections as follows,
``b``.- to repeat the previous list.
``p'' - to select states based on odd or even parity.
``r'' - to specify a range of decimal equivalents, i.e. from 10 to 50 (if n<=32).
``h1'' - to select states based on a hamming distance of 1 from the target state.
``h2'' - to select states based on a hamming distance of 2 from the target state.
Once set, the target state and list of aspiring pre-images are reviewed in a window (see #27.7).