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-- -*- coding: utf-8 -*-
--- status: Draft
--- author(s): MES
--- notes: This function is not functional yet
document {
Key => getNonUnit,
Headline => "retrieve a previously discovered non-unit",
Usage => "getNonUnit R",
Inputs => {
"R" => Ring => "in which division by a non-unit may have been attempted"
},
Outputs => {
RingElement => {"the non-unit, if any, or ", TO null}
},
"If a ring has been declared to be a field, using ", TO toField, " or ", TO frac, ", but a nonzero element is
found to not be a unit, this routine will return that element, otherwise ", TO null, " is returned.",
EXAMPLE lines ///
A = ZZ/101[a]/(a^2-1);
toField A
1//(a-1)
getNonUnit A
///,
"Warning: this function does not work yet for divisions attempted in the course
of computing a Gröbner basis or resolution.",
SeeAlso => { "toField", "frac" }
}
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