1. The DerUCP Algorithm Replay(P,C,G,…) Modified version of UCP: loop:
if the current partial plan P is a solution then exit
G = {refinement goals for P}
if there is a case C that matches some g in G then call Replay(P,C,G,…)
else nondeterministically select a refinement
Replay(P,C,G,…)
gC = the first refinement goal in the case C
if gC matches a refinement goal g in G then
dC = the refinement decision for gC
if dC can be applied to g then apply it
else exit
either call Replay recursively (to replay more of C)
or else exit
New C P
1st decision
2nd decision
3rd decision not applicable, so exit