Comment 4 for bug 1984070

The problem is that the continuous verifytapn engine supports only weights 1 on arcs. After the net in the example is unfolded, it creates net weights more than 1 on some arcs. For example 1'ssh + 2'vpn on the arc is not allowed but 1'ssh + 1'vpn is fine. 1'ssh + 1'ssh is not allowed either (as it is the same as 2'ssh). Also, inhibitor arcs create nets with higher weights (to the sum place). All this is fine for the discrete engine verifydtapn but for the continuous this does not work.

The fix is to detect this in the dialog (only for colored and timed nets) and if they contain forbidden expressions/inhibitor arcs, then disable the continuous verifytapn engine from the valid engine selections.