Figure 7.

The skip encoding. The read of Figure 6 is represented in the skip-3 alphabet. The symbols ⇓_j(j = 1, 2, 3) represent mismatches against the target (they are erroneous nucleotides) and the □ symbol represents a match (it is a correct nucleotide). The vertical bars indicate non-skipped positions (the potential start of a seed). The number j in ⇓_j indicates the number of nucleotides until the next non-skipped position. For j = 0 the next nucleotide is not skipped. Other features are as in Figure 6.