A few simple examples of short class definitions with modifiers are shown below, all being modifications of the superclass Real:
LowPassFilter20 is a modification of the model LowPassFilter1, with the changed values of ystart and T.
The two models LowPassFilter1 and LowPassFilter20 can be replaced by the single model LowPassFilter20B.
Take a look at some values of y at time=0.0001, time=10, time=20:
Simulate the second filter: