AssumeDomain -- an option to assume a ring is a domain

Description

AssumeDomain is an option used in various functions, to assume that a ring is an integral domain.

isFRational(...,AssumeDomain=>...) -- see isFRational -- whether a ring is F-rational
isFRegular(...,AssumeDomain=>...) -- see isFRegular -- whether a ring or pair is strongly F-regular
testElement(...,AssumeDomain=>...) -- see testElement -- find a test element of a ring
testIdeal(...,AssumeDomain=>...) -- see testIdeal -- compute a test ideal in a Q-Gorenstein ring
testModule(...,AssumeDomain=>...) -- see testModule -- find the parameter test module of a reduced ring