Wie "ist nicht gleich" in if-Abfrage?

[SirThornberry]

da gibt es mehrere möglichkeiten:

Delphi-Quellcode:

if (a <> b) then
  DoSomething;

Delphi-Quellcode:

if not (a = b) then
  DoSomething;

Delphi-Quellcode:

if (a < b) or (a > b) then
  DoSomething;

Delphi-Quellcode:

if (a = b) then
else
  DoSomething;