theorem Th45:
 for p being PartState of S
  holds DataPart Initialize p = DataPart p
 proof let p be PartState of S;
  thus DataPart Initialize p
        = DataPart p +* DataPart Start-At(0,S) by FUNCT_4:71
       .= DataPart p +* {} by Th20
       .= DataPart p;
 end;
