don't know it this can work, but
i have working, long equations that break down into basically 3parts:
If switch is set, then a & b, else just a. That is a repetition I am trying
to get rid of.

basically have: =IF($ab$2="x",AND(A=C,B=C),A=C)

trying to get rid of using a=c twice, thanks..
(a can stand alone, but b must be anded with a)
maybe something like:
=AND(A=C,IF($ab$2="x",b=c)) but 2nd part comes up as false, so not work..
=AND(A=C,IF($ab$2<"x","",b=c)