z bit acc.0

x1 bit b.0
x2 bit b.1
y1 bit b.2
y2 bit b.3

cseg at 0h 

    clr a
    mov b, a
_loop1:
    rl a

    ; y1 | ~x1
    mov c, y1
    orl c, /x1
    mov z, c

    ; y2 & x2 | x1
    mov c, y2
    anl c, x2
    orl c, x1

    ; ( y1 | ~x1 ) & ( y2 & x2 | x1 )
    anl c, z
    mov z, c


    inc b
    jnb b.3, _loop1

    mov p0, a

    clr a

_loop2:
    rl a

    mov c, y1
    orl c, /x1
    mov z, c
    mov c, y2
       anl c, x2
    orl c, x1
    anl c, z
    mov z, c

    mov z, c

    inc b
    jnb b.4, _loop2

    mov p2, a

    jmp $
end