The one global rule: 
    a single defstruct with all the fields

The aging slot rule:
    group slots in struct by when they are created so we can
    reset to some past point, at ease

The local global rule
    (defun x (&optional *x* *x*) 
        (x1))
    for all sub-calls in x1, *x* is a referable local copy.

The "?" rule- pick one from a range

The "!" rule- memo "?".