I tried to print the result in C-ish format like in the tutorial. I got the following error. Parameter no longer used. See GPTree.java for details. PARAMETER: pop.subpop.0.species.ind.tree.0.c ALSO: gp.tree.c SYSTEM EXITING FROM ERRORS Just thought I should put it up. Maybe the tutorial is out of date and doesn't work with the new ECJ version?