# QGorensteinIndex -- an option to specify the index of the canonical divisor, if known

## Description

When working in a $\mathbb{Q}$-Gorenstein ring $R$, frequently we must find a positive integer $N$ such that $N K_R$ is Cartier. This option allows this search to be bypassed if this integer is already known, by setting QGorensteinIndex => N.

## Functions with optional argument named QGorensteinIndex :

• "isFRegular(...,QGorensteinIndex=>...)" -- see isFRegular -- whether a ring or pair is strongly F-regular
• "testIdeal(...,QGorensteinIndex=>...)" -- see testIdeal -- compute a test ideal in a Q-Gorenstein ring

## For the programmer

The object QGorensteinIndex is .