On an ALU data sheet there are logic formulae showing the results that will be output for various inputs.


(Second from last row on page 3.)

I assume that A+B means bitwise A OR B, this would follow, as the plus in a circle is XOR.

Does AB mean bitwise A AND B?

  • \$\begingroup\$ It would follow, because the arithmetic plus is indicated by PLUS. And since the multiplication is not among the parts capability (as indicated on the first page), AB would mean bitwise A AND B. \$\endgroup\$
    – Eugene Sh.
    Jun 23, 2016 at 15:48
  • \$\begingroup\$ A lot of sources are already on the google search, no offense I don't think there is a question here. \$\endgroup\$
    – MaMba
    Jun 23, 2016 at 16:16
  • \$\begingroup\$ Unless it is a regex expression your deduction is true. \$\endgroup\$
    – user105652
    Jun 23, 2016 at 22:29

2 Answers 2


Yes, when written as multiplication in normal math, it means AND in Boolean logic. This does make some sense when you think about it. Make a truth table of multiplying two value that can be either 0 or 1. The result is 0 except when both are 1, then the result is 1. That's exactly what AND does.

This logic doesn't really follow for "+", unless you consider 0 FALSE and anything else TRUE.

  • \$\begingroup\$ So many words instead just yes \$\endgroup\$
    – user76844
    Jun 23, 2016 at 16:31
  • 5
    \$\begingroup\$ A one word answer is pretty much considered useless, and quickly downvoted. Points for the explanation. \$\endgroup\$
    – R Drast
    Jun 23, 2016 at 16:46
  • 2
    \$\begingroup\$ unless you consider 0 FALSE and anything else TRUE Like most C-derived programming languages, for example :) \$\endgroup\$
    – cat
    Jun 23, 2016 at 18:25

You are right AB mean A AND B . It is faster to write AB than A dot B or A AND B

  • 5
    \$\begingroup\$ Is it also faster to write "right" than it is to write "write" right? \$\endgroup\$
    – Ben Voigt
    Jun 23, 2016 at 15:51
  • \$\begingroup\$ @BenVoigt Didn't realize the edit, filled the comment box with alternating "right" and "write" to measure typing speed. Only then I noticed the earlier revision. \$\endgroup\$
    – Kroltan
    Jun 24, 2016 at 2:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.