-- Hardware
group: Hardware 

Product = {
maker:string,model:string,type:string
IBM,'Office PC 2010',PC
IBM,'Office PC 2010a',PC
'ACME Corp','Red tower',PC
'ACME Corp','Green tower',PC
'ACME Corp','Blue tower',PC
HP,'Laptop X100',Laptop
'ACME Corp','Red laptop',Laptop
HP,'Laserprint 1000',Printer
HP,'Inkprint 300',Printer
}

PC = {
model:string,speed:number,ram:number,hd:number,price:number
'Office PC 2010',2.5,2048,500,600
'Office PC 2010a',2.7,4096,500,800
'Red tower',3.5,6192,1000,900
'Green tower',3.2,4096,500,770
'Blue tower',2.5,3012,400,400
}

Laptop = {
model:string,speed:number,ram:number,hd:number,screen:string,price:number
'Laptop X100',3.0,4084,500,'1920x1092',800
'Red laptop',3.3,6192,10000,'2560×1440',1200
}

Printer = {
model:string,color:boolean,type:string,price:number
'Laserprint 1000',false,Laser,700
'Inkprint 300',true,Ink,500
}