<pre>
class Monitor

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

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