ORG 0000h        ; Start of program
    MOVLW 0x0A       ; Load the value 0x0A into WREG
    MOVWF 0x20       ; Move the value from WREG to register 0x20
    MOVLW 0x03       ; Load the value 0x03 into WREG
    SUBWF 0x20, W    ; Subtract the value in WREG from register 0x20, result in WREG
    GOTO $           ; Infinite loop to stop the program
    END              ; End of program