Calc isn't accepting new nested "IF" functions; previously worked fine. How to fix?

LibreOffice Version:, Build ID: 420m0(Build:2)

Computer is laptop (iBUYPOWER CZ-17; motherboard is proprietary, but similar to MSI-1762) with the following specs:
CPU: Intel Core i7-3630QM @ 2.40 GHz
RAM: (4x) GSKILL DDR3-1333 MHz 4GB SO-DIMM (16.0 GB installed; 15.9 GB usable)
SSD: Mushkin Enhanced Reactor 1TB

OS: Linux Mint Rebecca Cinnamon

And an example is …? Beside that 4.2 is rather old.


The specs may not be relevant. But: In what way did Calc “not accept” the formula? Did you copy/paste the formula from some kind of text editor? If you look at the “formula” you posted above you find “typographical quotes” e.g. Not suitable for formulae! Use the tool for inserting code here. Try =IF(AND(B$3<>"";$A4>0;$A4<=B$3);"POS";(IF(AND($A4=0;B$3<>"";B$3>=0);"Q1Z";IF(AND($A4<0;B$3<>"";B$3>=0);"-N-";IF(AND($A4<0;B$3<>"";B$3<0);"NEG";""))))) copied from my comment. It might work.

Can’t believe I missed that! I did the setup in Writer, then C&P. DOH!

SOLVED. Refer to comment by Lupp.

Thanks to the whole community of helpful folks; special thanks to Lupp for the helpful answer.