@Stefan Schippers I saw your commit, adding prev(). Thanks a lot! I was wondering if the graph below is intended behavior. It shows 3 pulse sources all 50% duty, 2 with period 10ns (D0) from 0 to 1.8 and (D0i) from 1.8 to 0 and one with period 20ns (D1) from 0 to 1.8. When I combine D0 with D1 the result it is a peak, while I was expecting a constant 1.8