<pre>
class Monitor

InputReal x, y;  // plant output
OutputBoolean wy;

Boolean wz;

initial equation

wy = false;
equation
wz = (time > 10) and ((x < 10) or (x > 20)) and ((y < 0.5*x) or (y > 0.7*x)) ;
algorithm
when edge(wz) then
wy := true;
end when;
end Monitor;
</pre>