normal.lib
library before calling the genus
command, or you'll get an
error message.
sage: singular.lib('normal.lib') sage: R = singular.ring(0,'(x,y)','dp') sage: i2 = singular.ideal('y9 - x2*(x-1)^9 + x') sage: i2.genus() 40
Note that the genus can be much smaller than the degree:
sage: i = singular.ideal('y9 - x2*(x-1)^9') sage: i.genus() 0
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