The translator should automatically
vectorize (or "matricize") this function. For example, Delta([1,2;3,4]) returns {1,1}.
function Delta
extends Modelica.Icons.Function;
input Real u[2] "Vector of size two" annotation(
Dialog(__Dymola_label = "<html><i>u</i></html>"));
output Real Delta "Second entry minus the first entry" annotation(
Dialog(__Dymola_label = "<html>Δ</html>"));
end Delta;