Your IF() statement is lacking a condition.

As you have it your statement is saying:

IF B4<$B$2 do this IF(C4<$C$2,0,1)

otherwise - this is what is lacking. So Excel simply says FALSE.

Do you want some value if B4<$B$2 is TRUE but the IF(C4<$C$2,0,1) when it's FALSE.

If so:

=IF(B4<$B$2,"XXX",IF(C4<$C$2,0,1)) replace the "XXX" with the result you want when B4<$B$2 is TRUE