For , the omitted point has codimension at least two in the normal integral scheme . Regular functions extend across such a subset, so
Thus
on , and it is a coherent sheaf because it corresponds to the one-dimensional -vector space .
The complement of a rational point in is . Its regular functions are , which is infinite-dimensional over . Its pushforward to is therefore quasi-coherent but not coherent.
For an example on , choose a projective line through . Then
is closed in . For the closed immersion , the sheaf is coherent, but
Consequently is not coherent on .