Figure 2
Location of a new EST internal factor si+1given previous computed factors s2, ..., s
i
. (a) Consecutive sequence components c1 ... c
j
are tested to find the first one that allows the identification of a genomic region that optimally aligns factor si+1(i.e. alignment extension on one or both sides of the component): such a region is determined in (b) by the component c
j
. Figure (b) shows that some intervening positions (sequence x) may occur between factor s
i
and si+1. Indeed, in this case the placement of si+1gives the correct right end of previous factor s
i
, since the larger factor 
inducing canonical splice sites on the genomic sequence can be optimally aligned before si+1thus leading to an optimal location of both s
i
and si+1.