Debugging test 2: 
- the specific slopes for the cocomo parameters are set in
  model-defaults.lisp. Have the right ranges and slopes been assigned
  to the right variables?

The range for flex originally used (make-r25), indicating a range of low
to very high.  The range for flex is actually very low to very high, so
(make-r15) should be used.

Original:
(flex . ,(make-sf :range (make-r25) :effort (make-sfs) :rsf (make-rsf) :dsf (make-dsf) :csf (make-csf)))

Fix:
(flex . ,(make-sf :range (make-r15) :effort (make-sfs) :rsf (make-rsf) :dsf (make-dsf) :csf (make-csf)))