What do && and || mean? You'll never see a doubled character as a operator in HL's scripting language. Do you just mean & and |, and you're pulling in terms from another language?
Also, do you want to use booleans with a script, or are you using booleans in a tag expression? The answer is different in each case
If your question is about tag expressions, here's that section of the wiki:
http://hlkitwiki.wolflair.com/index....ag_Expressions
For scripts, you'll have to be clever with addition and subtraction and multiplication, because the standard if () then can't take booleans.
But,
if (A + B <> 0) then
ends up meaning A or B, as long as both A and B are things that are false at 0 and true if <> 0, and
if (A + B = 2) then
ends up meaning A & B, as long as both A and B are things that are false at 0 and true at 1 (but in this case, it doesn't work if they can be values > 1).