 For the same reason , the version history of a distributed revision control system generally has the structure of a directed acyclic graph , in which there is a vertex for each revision and an edge connecting pairs of revisions that were directly derived from each other . These are not trees in general due to merges . 
 For the same reason , the version history of a distributed revision control system generally <a href='got' title='1'><mark>has</mark></a> the structure of a directed acyclic graph , in which <a href='dey_it' title='2'><mark>there</mark></a> is a vertex for each revision and an edge connecting pairs of revisions <a href='null_relcl' title='3'><mark>that</mark></a><a href='uninflect' title='4'><mark>were</mark></a> directly derived from each other . These <a href='negative_concord' title='5'><mark>are</mark></a> <a href='negative_concord' title='6'><mark>not</mark></a><a href='negative_concord' title='7'><mark>trees</mark></a> in general due to merges . 
For the same reason , the version history of a distributed revision control system generally got da structure of a directed acyclic graph , in which it is a vertex for each revision and an edge connecting pairs of revisions was directly derived from each other . dem ain't no trees in general due to merges .