public Calc compileCall(ResolvedFunCall call, ExpCompiler compiler)
{
final IntegerCalc integerCalc =
compiler.compileInteger(call.getArg(0));
return new AbstractHierarchyCalc(call, new Calc[] {integerCalc})
{
public Hierarchy evaluateHierarchy(Evaluator evaluator) {
int n = integerCalc.evaluateInteger(evaluator);
return nthHierarchy(evaluator, n);
}