title: Is there a way to make Mathematica treat a symbol as real?
body: <p>Is it possible in Mathematica to set the symbols 'a' and 'b' as reals so when I type   'z = a+<strong>I</strong> b;Conjugate[z]' I get 'a-<strong>I</strong> b' and not 'Conjugate[a]-<strong>I</strong> Conjugate[b]'?</p>