logical operator Definition
An operator that performs a logic operation on nodes, groups, or numbers.
AHDL logical operators are NOT (!),
                  AND (&), NAND
                  (!&), OR (#),
                  NOR (!#), XOR
                  ($), and XNOR (!$).
               
VHDL logical operators are AND, NAND,
                  OR, NOR, XOR,
                  XNOR, and NOT.
               
Verilog HDL logical operators are logical and
                  (&&), logical or
                  (||), and logical negation (!).