if( debug ) Gpr.debug("Tree: " + tree.toStringTree());
Tree child = tree.getChild(0);
Value a = new Value(child, this);
Value b = new Value(tree.getChild(1), this);
Value mean = new Value(tree.getChild(2), this);
MembershipFunction membershipFunction = new MembershipFunctionGenBell(a, b, mean);
return membershipFunction;
}