474—If they belong to the same line, the nearer in degree takes precedence.
475—If they are equal in degree, the one with the stronger kinship takes precedence: one related through both parents over one related through the father alone.
476—For every residuary heir other than sons and brothers, his sister inherits nothing alongside him.
477—When the prescribed shares together exceed the estate, so that the heirs proportionately reduce one another’s shares, the denominator is increased1 in accordance with their prescribed shares:
1—If the heirs are a husband, a mother, and a sister who is not a maternal half-sister, the base denominator2 is six, and it is increased to eight3.
2—If there is also a maternal half-brother, the ruling is the same.
3—If there are two maternal half-brothers, it is increased to nine.
4—If there are two sisters who are not maternal half-sisters, it is increased to ten.