ExamplePhone1 display LCD GSM CPU keyboard ExamplePhone2 display OLED GSM touchscreen ExampleTablet1 display AMOLED HSPA CPU 4 touchscreen ExamplePhone3 display LCD GSM CPU 4 keyboard ExampleTablet2 display AMOLED HSPA CPU 4 keyboard abstract AndroidDevice1 xor display LCD OLED AMOLED [ no keyboard ] GSM HSPA ? CPU 1..4 xor input keyboard touchscreen abstract AndroidPhone : AndroidDevice [ GSM ] [ # CPU < 4 ] abstract AndroidDevice xor display LCD OLED AMOLED [ no keyboard ] GSM ? HSPA ? CPU 1..4 xor input keyboard touchscreen AndroidPhone4 : AndroidPhone display AMOLED GSM HSPA CPU 2 input touchscreen