TrySolveOverPolynomials(AngouriMath.Entity[][],AngouriMath.Entity[],AngouriMath.Entity[]@)'s reading and elimination run first on the
image of the system modulo LiftingPrime, to learn whether the ones over
Q decline: the same readings, pivots, products and exact divisions, in
residues that cost a machine multiplication each where the rationals of a minor cost
a greatest common divisor. The Bareiss intermediates are minors, so each is the image
of the one over Q and has no monomial that one lacks; a product of more than
MaxIntermediateTerms terms here, a quotient of
more, an exponent past MaxDegree, an entry the
reading refuses or a row that reduces to 0 = c is therefore one there too, and
the solve over Q refuses it. Anything else -- an image that does not exist, a
division that does not come out, a remainder too large to hold -- says nothing, and
the solve over Q runs as it did.