Common.ecore:
-------------
package common : common = 'http://www.example.org/common'
{
	class Person
	{
		attribute name : String[?];
	}
}

MyModel.ecore:
--------------

import common : 'Common.ecore#/' ;

package mymodel : mymodel = 'http://www.example.org/mymodel'
{
	class MyPerson
	{
		property commonPerson : common::Person[?];
		attribute name : String[?] { derived transient volatile }
		{
			initial: commonPerson?.name;
		}
	}
}

import org.eclipse.ocl.xtext.oclinecore.OCLinEcoreStandaloneSetup;

import mymodel.MyPerson;
import mymodel.MymodelFactory;

public class ImportTest {

	public static void main(String[] args) {

		OCLinEcoreStandaloneSetup.doSetup();

		MyPerson myPerson = MymodelFactory.eINSTANCE.createMyPerson();
		System.out.println(myPerson.getName());
	}

}