Re: if statement brain cramp

On 2/27/2019 11:35 AM, Joe Pluta wrote:

You've gotten all the specific answers you need, but I thought I'd chime
in with the more generalized approach. This is Boolean logic or more
precisely Boolean algebra (which is what got me into programming lo
those many decades ago).  The specific case is DeMorgan's law, which
states:

not (A and B) = (not A or not B)

A: SML010 <> 5
B: M1PLIN = *blanks

not A: SML010 = 5
not B: M1PLIN <> *blanks
(not A or not B): (SML010 = 5 or M1PLIN <> *blanks)

I use Boolean algebra all the time to simplify complex business logic
(especially IF statements that have grown over time).  A nice page for
it exists here:

https://www.ics.uci.edu/~pattis/ICS-31/lectures/simplify/lecture.html

Good reference.

Although more often applied to digital electronics than to software, the
general principles hold. If one is a visual learner, the graphical
depiction of logic gates might assist in digesting how De Morgan's laws
work with real-world problems.

Another tool that might be helpful is a Karnaugh map.
I don't need one often, but when I do...