The methodology and theory behind the system is described in the following journal paper:

Christiansen, H., Automated reasoning with a constraint-based metainterpreter, Journal of Logic Programming, 1998. Vol 37(1-3) Oct-Dec 98, pp. 213-253

Other publications:

"Implicit program synthesis by a reversible metainterpreter"
Christiansen, H., Invited talk, Proc. of LOPSTR'97 (ed. N. Fuchs), Lecture Notes in Computer Science 1463, pp. 87-106, 1998
"Abduction and induction in a metalogic framework"
Christiansen, H., Chapter in the book Abductive and Inductive Reasoning: Essays on their Relation and Integration, (P. Flach, A. Kakas, eds.). To appear 1999.

Find other related references at Henning Christiansen's publication page.