In mathematics (i.e. boolean algebra) it is common to denote * for and and + for or IFF the alphabet is restricted to boolean values 0 and 1.

NOTE: 1 + 1 is mapped to 1 there.

This works in Perl somehow. (1+1 =2 is still true)

But don't ! It's not recommended ... rather a workaround in languages without boolean operators.²

Just sketch the truth table to see how it works.

Better use && and || instead.

> Y = (A & B)

that's definitely wrong, because & is for a bitwise and not a logical.

UPDATE

to elaborate more: the standard false value in Perl is not 0 but empty string '' . While the latter will be evaluated to 0 in arithmetic operations it might cause a confusion.

DB<7> print !!0

DB<8> print  !!1
   1
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footnotes

²) and only for simple cases, b/c you risk a number overflow when multiplying true values.

> perl -E "say ((1+1) * (1+1) * (1+1));"
8
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