\newcommand\morf[4][\to]{#2\colon #3#1 #4} % \morf{f}{A}{B} = f\colon A\to B \newcommand\diff[3][\partial]{\frac{#1 #2}{#1 #3}} \newcommand\inverse{^{-1}} % hvis man tit skal skrive ^{-1}, ie $X\inverse$ \newcommand\isomorph{\cong} % \cong anvendes ofte til dette \newcommand\homotopyeq{\simeq} % fra topologi \newcommand\DistAs{\sim} % X \DistAs N(0,1) \newcommand\ObsFromDist{\sim\sim} % observation fra variabel distribueret som... \newcommand\DistEq{\stackrel{\smash{\scriptscriptstyle(d)}{=}}} % lighed i distribution