public void eval(
final EvolutionState state,
final int thread,
final GPData input,
final ADFStack stack,
final GPIndividual individual,
final Problem problem) {
RegressionData rd = ((RegressionData) (input));
children[0].eval(state, thread, input, stack, individual, problem);
rd.x = /*Strict*/ Math.exp(rd.x);
}