SYSML17 — Fig D.41 should be bdd with instance specs & slot values, not ibd with default values

Figure D.41 is unchanged from SysML 1.0. The purpose of the figure was to illustrate how part serial numbers can be handled in SysML, but it was created without any practical experience in instance specification slot values. Instance slot values provide a more concrete representation of instance-level values such as serial numbers. A serial number should never be treated as a default value, because each serial number needs to be unique.