Indicate discrete variable changing
change(v)
Is expanded into "(v<>pre(v))". The same restrictions as for the pre() operator apply.
model BothEdges
Boolean u;
Integer i;
equation
u = Modelica.Math.sin(time) > 0.5;
when change(u) then
i = pre(i) + 1;
end when;
end BothEdges;
