storing location in the sequence of vertices so it now contains the symbol for emptiness (some pre-define negative number).

### Merging triggered with active vertices

Triggered vertices are now merged to the sequence of active vertices.

### Check active vertices for potential loss of activity

For each active vertex $Q$ look at all edges from $Q$. If there is no active edge whose source is $Q$, then $Q$ should not be active any longer.

### Condensing the sequence of active vertices

After previous few steps some vertices may stop being active in which case they should be removed from the sequence.

Step 9: Finalizing active edges
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We first need to merge the triggered edges with active edges. Then all just used edges have to become used and their source has to be re-set so it is not equal to any of the endpoints. Those used edges should be removed from the sequence of active edges. The remaining final step is to condense the obtained sequence so there are no used edges in the sequence of active edges.

Large sets of active vertices
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In this section we will prove that it is possible for the set of active vertices 