def test_Algebra__unify():
assert ZZ.unify(ZZ) == ZZ
assert QQ.unify(QQ) == QQ
assert ZZ.unify(QQ) == QQ
assert QQ.unify(ZZ) == QQ
assert EX.unify(EX) == EX
assert ZZ.unify(EX) == EX
assert QQ.unify(EX) == EX
assert EX.unify(ZZ) == EX
assert EX.unify(QQ) == EX
assert ZZ.poly_ring('x').unify(EX) == EX
assert ZZ.frac_field('x').unify(EX) == EX
assert EX.unify(ZZ.poly_ring('x')) == EX
assert EX.unify(ZZ.frac_field('x')) == EX
assert ZZ.poly_ring('x', 'y').unify(EX) == EX
assert ZZ.frac_field('x', 'y').unify(EX) == EX
assert EX.unify(ZZ.poly_ring('x', 'y')) == EX
assert EX.unify(ZZ.frac_field('x', 'y')) == EX
assert QQ.poly_ring('x').unify(EX) == EX
assert QQ.frac_field('x').unify(EX) == EX
assert EX.unify(QQ.poly_ring('x')) == EX
assert EX.unify(QQ.frac_field('x')) == EX
assert QQ.poly_ring('x', 'y').unify(EX) == EX
assert QQ.frac_field('x', 'y').unify(EX) == EX
assert EX.unify(QQ.poly_ring('x', 'y')) == EX
assert EX.unify(QQ.frac_field('x', 'y')) == EX
assert ZZ.poly_ring('x').unify(ZZ) == ZZ.poly_ring('x')
assert ZZ.poly_ring('x').unify(QQ) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(ZZ) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(QQ) == QQ.poly_ring('x')
assert ZZ.unify(ZZ.poly_ring('x')) == ZZ.poly_ring('x')
assert QQ.unify(ZZ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.poly_ring('x', 'y').unify(ZZ) == ZZ.poly_ring('x', 'y')
assert ZZ.poly_ring('x', 'y').unify(QQ) == QQ.poly_ring('x', 'y')
assert QQ.poly_ring('x', 'y').unify(ZZ) == QQ.poly_ring('x', 'y')
assert QQ.poly_ring('x', 'y').unify(QQ) == QQ.poly_ring('x', 'y')
assert ZZ.unify(ZZ.poly_ring('x', 'y')) == ZZ.poly_ring('x', 'y')
assert QQ.unify(ZZ.poly_ring('x', 'y')) == QQ.poly_ring('x', 'y')
assert ZZ.unify(QQ.poly_ring('x', 'y')) == QQ.poly_ring('x', 'y')
assert QQ.unify(QQ.poly_ring('x', 'y')) == QQ.poly_ring('x', 'y')
assert ZZ.frac_field('x').unify(ZZ) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(QQ) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(ZZ) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ) == QQ.frac_field('x')
assert ZZ.unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert QQ.unify(ZZ.frac_field('x')) == EX # QQ.frac_field('x')
assert ZZ.unify(QQ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x', 'y').unify(ZZ) == ZZ.frac_field('x', 'y')
assert ZZ.frac_field('x', 'y').unify(QQ) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x', 'y').unify(ZZ) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x', 'y').unify(QQ) == QQ.frac_field('x', 'y')
assert ZZ.unify(ZZ.frac_field('x', 'y')) == ZZ.frac_field('x', 'y')
assert QQ.unify(ZZ.frac_field('x', 'y')) == EX # QQ.frac_field('x','y')
assert ZZ.unify(QQ.frac_field('x', 'y')) == EX # QQ.frac_field('x','y')
assert QQ.unify(QQ.frac_field('x', 'y')) == QQ.frac_field('x', 'y')
assert ZZ.poly_ring('x').unify(ZZ.poly_ring('x')) == ZZ.poly_ring('x')
assert ZZ.poly_ring('x').unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(ZZ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.poly_ring('x', 'y').unify(ZZ.poly_ring('x')) == ZZ.poly_ring(
'x', 'y')
assert ZZ.poly_ring('x', 'y').unify(QQ.poly_ring('x')) == QQ.poly_ring(
'x', 'y')
assert QQ.poly_ring('x', 'y').unify(ZZ.poly_ring('x')) == QQ.poly_ring(
'x', 'y')
assert QQ.poly_ring('x', 'y').unify(QQ.poly_ring('x')) == QQ.poly_ring(
'x', 'y')
assert ZZ.poly_ring('x').unify(ZZ.poly_ring('x', 'y')) == ZZ.poly_ring(
'x', 'y')
assert ZZ.poly_ring('x').unify(QQ.poly_ring('x', 'y')) == QQ.poly_ring(
'x', 'y')
assert QQ.poly_ring('x').unify(ZZ.poly_ring('x', 'y')) == QQ.poly_ring(
'x', 'y')
assert QQ.poly_ring('x').unify(QQ.poly_ring('x', 'y')) == QQ.poly_ring(
'x', 'y')
assert ZZ.poly_ring('x', 'y').unify(ZZ.poly_ring('x',
'z')) == ZZ.poly_ring(
'x', 'y', 'z')
assert ZZ.poly_ring('x', 'y').unify(QQ.poly_ring('x',
'z')) == QQ.poly_ring(
'x', 'y', 'z')
assert QQ.poly_ring('x', 'y').unify(ZZ.poly_ring('x',
'z')) == QQ.poly_ring(
'x', 'y', 'z')
assert QQ.poly_ring('x', 'y').unify(QQ.poly_ring('x',
'z')) == QQ.poly_ring(
'x', 'y', 'z')
assert ZZ.frac_field('x').unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert QQ.frac_field('x').unify(ZZ.frac_field('x')) == QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x', 'y').unify(ZZ.frac_field('x')) == ZZ.frac_field(
'x', 'y')
assert ZZ.frac_field('x', 'y').unify(QQ.frac_field('x')) == QQ.frac_field(
'x', 'y')
assert QQ.frac_field('x', 'y').unify(ZZ.frac_field('x')) == QQ.frac_field(
'x', 'y')
assert QQ.frac_field('x', 'y').unify(QQ.frac_field('x')) == QQ.frac_field(
'x', 'y')
assert ZZ.frac_field('x').unify(ZZ.frac_field('x', 'y')) == ZZ.frac_field(
'x', 'y')
assert ZZ.frac_field('x').unify(QQ.frac_field('x', 'y')) == QQ.frac_field(
'x', 'y')
assert QQ.frac_field('x').unify(ZZ.frac_field('x', 'y')) == QQ.frac_field(
'x', 'y')
assert QQ.frac_field('x').unify(QQ.frac_field('x', 'y')) == QQ.frac_field(
'x', 'y')
assert ZZ.frac_field('x', 'y').unify(ZZ.frac_field('x',
'z')) == ZZ.frac_field(
'x', 'y', 'z')
assert ZZ.frac_field('x', 'y').unify(QQ.frac_field('x',
'z')) == QQ.frac_field(
'x', 'y', 'z')
assert QQ.frac_field('x', 'y').unify(ZZ.frac_field('x',
'z')) == QQ.frac_field(
'x', 'y', 'z')
assert QQ.frac_field('x', 'y').unify(QQ.frac_field('x',
'z')) == QQ.frac_field(
'x', 'y', 'z')
assert ZZ.poly_ring('x').unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert ZZ.poly_ring('x').unify(
QQ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.poly_ring('x').unify(
ZZ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.poly_ring('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.poly_ring('x', 'y').unify(ZZ.frac_field('x')) == ZZ.frac_field(
'x', 'y')
assert ZZ.poly_ring('x', 'y').unify(
QQ.frac_field('x')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x', 'y').unify(
ZZ.frac_field('x')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x', 'y').unify(QQ.frac_field('x')) == QQ.frac_field(
'x', 'y')
assert ZZ.poly_ring('x').unify(ZZ.frac_field('x', 'y')) == ZZ.frac_field(
'x', 'y')
assert ZZ.poly_ring('x').unify(QQ.frac_field(
'x', 'y')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x').unify(ZZ.frac_field(
'x', 'y')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x').unify(QQ.frac_field('x', 'y')) == QQ.frac_field(
'x', 'y')
assert ZZ.poly_ring('x', 'y').unify(ZZ.frac_field('x',
'z')) == ZZ.frac_field(
'x', 'y', 'z')
assert ZZ.poly_ring('x', 'y').unify(QQ.frac_field(
'x', 'z')) == EX # QQ.frac_field('x','y','z')
assert QQ.poly_ring('x', 'y').unify(ZZ.frac_field(
'x', 'z')) == EX # QQ.frac_field('x','y','z')
assert QQ.poly_ring('x', 'y').unify(QQ.frac_field('x',
'z')) == QQ.frac_field(
'x', 'y', 'z')
assert ZZ.frac_field('x').unify(ZZ.poly_ring('x')) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(
QQ.poly_ring('x')) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(
ZZ.poly_ring('x')) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ.poly_ring('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x', 'y').unify(ZZ.poly_ring('x')) == ZZ.frac_field(
'x', 'y')
assert ZZ.frac_field('x', 'y').unify(
QQ.poly_ring('x')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x', 'y').unify(
ZZ.poly_ring('x')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x', 'y').unify(QQ.poly_ring('x')) == QQ.frac_field(
'x', 'y')
assert ZZ.frac_field('x').unify(ZZ.poly_ring('x', 'y')) == ZZ.frac_field(
'x', 'y')
assert ZZ.frac_field('x').unify(QQ.poly_ring(
'x', 'y')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(ZZ.poly_ring(
'x', 'y')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(QQ.poly_ring('x', 'y')) == QQ.frac_field(
'x', 'y')
assert ZZ.frac_field('x', 'y').unify(ZZ.poly_ring('x',
'z')) == ZZ.frac_field(
'x', 'y', 'z')
assert ZZ.frac_field('x', 'y').unify(QQ.poly_ring(
'x', 'z')) == EX # QQ.frac_field('x','y','z')
assert QQ.frac_field('x', 'y').unify(ZZ.poly_ring(
'x', 'z')) == EX # QQ.frac_field('x','y','z')
assert QQ.frac_field('x', 'y').unify(QQ.poly_ring('x',
'z')) == QQ.frac_field(
'x', 'y', 'z')
raises(UnificationFailed,
"ZZ.poly_ring('x','y').unify(ZZ, gens=('y', 'z'))")
raises(UnificationFailed,
"ZZ.unify(ZZ.poly_ring('x','y'), gens=('y', 'z'))")
def test_Algebra__unify():
assert ZZ.unify(ZZ) == ZZ
assert QQ.unify(QQ) == QQ
assert ZZ.unify(QQ) == QQ
assert QQ.unify(ZZ) == QQ
assert EX.unify(EX) == EX
assert ZZ.unify(EX) == EX
assert QQ.unify(EX) == EX
assert EX.unify(ZZ) == EX
assert EX.unify(QQ) == EX
assert ZZ.poly_ring('x').unify(EX) == EX
assert ZZ.frac_field('x').unify(EX) == EX
assert EX.unify(ZZ.poly_ring('x')) == EX
assert EX.unify(ZZ.frac_field('x')) == EX
assert ZZ.poly_ring('x','y').unify(EX) == EX
assert ZZ.frac_field('x','y').unify(EX) == EX
assert EX.unify(ZZ.poly_ring('x','y')) == EX
assert EX.unify(ZZ.frac_field('x','y')) == EX
assert QQ.poly_ring('x').unify(EX) == EX
assert QQ.frac_field('x').unify(EX) == EX
assert EX.unify(QQ.poly_ring('x')) == EX
assert EX.unify(QQ.frac_field('x')) == EX
assert QQ.poly_ring('x','y').unify(EX) == EX
assert QQ.frac_field('x','y').unify(EX) == EX
assert EX.unify(QQ.poly_ring('x','y')) == EX
assert EX.unify(QQ.frac_field('x','y')) == EX
assert ZZ.poly_ring('x').unify(ZZ) == ZZ.poly_ring('x')
assert ZZ.poly_ring('x').unify(QQ) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(ZZ) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(QQ) == QQ.poly_ring('x')
assert ZZ.unify(ZZ.poly_ring('x')) == ZZ.poly_ring('x')
assert QQ.unify(ZZ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.poly_ring('x','y').unify(ZZ) == ZZ.poly_ring('x','y')
assert ZZ.poly_ring('x','y').unify(QQ) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x','y').unify(ZZ) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x','y').unify(QQ) == QQ.poly_ring('x','y')
assert ZZ.unify(ZZ.poly_ring('x','y')) == ZZ.poly_ring('x','y')
assert QQ.unify(ZZ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert ZZ.unify(QQ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert QQ.unify(QQ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert ZZ.frac_field('x').unify(ZZ) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(QQ) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(ZZ) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ) == QQ.frac_field('x')
assert ZZ.unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert QQ.unify(ZZ.frac_field('x')) == EX # QQ.frac_field('x')
assert ZZ.unify(QQ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x','y').unify(ZZ) == ZZ.frac_field('x','y')
assert ZZ.frac_field('x','y').unify(QQ) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(ZZ) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(QQ) == QQ.frac_field('x','y')
assert ZZ.unify(ZZ.frac_field('x','y')) == ZZ.frac_field('x','y')
assert QQ.unify(ZZ.frac_field('x','y')) == EX # QQ.frac_field('x','y')
assert ZZ.unify(QQ.frac_field('x','y')) == EX # QQ.frac_field('x','y')
assert QQ.unify(QQ.frac_field('x','y')) == QQ.frac_field('x','y')
assert ZZ.poly_ring('x').unify(ZZ.poly_ring('x')) == ZZ.poly_ring('x')
assert ZZ.poly_ring('x').unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(ZZ.poly_ring('x')) == QQ.poly_ring('x')
assert QQ.poly_ring('x').unify(QQ.poly_ring('x')) == QQ.poly_ring('x')
assert ZZ.poly_ring('x','y').unify(ZZ.poly_ring('x')) == ZZ.poly_ring('x','y')
assert ZZ.poly_ring('x','y').unify(QQ.poly_ring('x')) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x','y').unify(ZZ.poly_ring('x')) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x','y').unify(QQ.poly_ring('x')) == QQ.poly_ring('x','y')
assert ZZ.poly_ring('x').unify(ZZ.poly_ring('x','y')) == ZZ.poly_ring('x','y')
assert ZZ.poly_ring('x').unify(QQ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x').unify(ZZ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert QQ.poly_ring('x').unify(QQ.poly_ring('x','y')) == QQ.poly_ring('x','y')
assert ZZ.poly_ring('x','y').unify(ZZ.poly_ring('x','z')) == ZZ.poly_ring('x','y','z')
assert ZZ.poly_ring('x','y').unify(QQ.poly_ring('x','z')) == QQ.poly_ring('x','y','z')
assert QQ.poly_ring('x','y').unify(ZZ.poly_ring('x','z')) == QQ.poly_ring('x','y','z')
assert QQ.poly_ring('x','y').unify(QQ.poly_ring('x','z')) == QQ.poly_ring('x','y','z')
assert ZZ.frac_field('x').unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert QQ.frac_field('x').unify(ZZ.frac_field('x')) == QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x','y').unify(ZZ.frac_field('x')) == ZZ.frac_field('x','y')
assert ZZ.frac_field('x','y').unify(QQ.frac_field('x')) == QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(ZZ.frac_field('x')) == QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(QQ.frac_field('x')) == QQ.frac_field('x','y')
assert ZZ.frac_field('x').unify(ZZ.frac_field('x','y')) == ZZ.frac_field('x','y')
assert ZZ.frac_field('x').unify(QQ.frac_field('x','y')) == QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(ZZ.frac_field('x','y')) == QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(QQ.frac_field('x','y')) == QQ.frac_field('x','y')
assert ZZ.frac_field('x','y').unify(ZZ.frac_field('x','z')) == ZZ.frac_field('x','y','z')
assert ZZ.frac_field('x','y').unify(QQ.frac_field('x','z')) == QQ.frac_field('x','y','z')
assert QQ.frac_field('x','y').unify(ZZ.frac_field('x','z')) == QQ.frac_field('x','y','z')
assert QQ.frac_field('x','y').unify(QQ.frac_field('x','z')) == QQ.frac_field('x','y','z')
assert ZZ.poly_ring('x').unify(ZZ.frac_field('x')) == ZZ.frac_field('x')
assert ZZ.poly_ring('x').unify(QQ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.poly_ring('x').unify(ZZ.frac_field('x')) == EX # QQ.frac_field('x')
assert QQ.poly_ring('x').unify(QQ.frac_field('x')) == QQ.frac_field('x')
assert ZZ.poly_ring('x','y').unify(ZZ.frac_field('x')) == ZZ.frac_field('x','y')
assert ZZ.poly_ring('x','y').unify(QQ.frac_field('x')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x','y').unify(ZZ.frac_field('x')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x','y').unify(QQ.frac_field('x')) == QQ.frac_field('x','y')
assert ZZ.poly_ring('x').unify(ZZ.frac_field('x','y')) == ZZ.frac_field('x','y')
assert ZZ.poly_ring('x').unify(QQ.frac_field('x','y')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x').unify(ZZ.frac_field('x','y')) == EX # QQ.frac_field('x','y')
assert QQ.poly_ring('x').unify(QQ.frac_field('x','y')) == QQ.frac_field('x','y')
assert ZZ.poly_ring('x','y').unify(ZZ.frac_field('x','z')) == ZZ.frac_field('x','y','z')
assert ZZ.poly_ring('x','y').unify(QQ.frac_field('x','z')) == EX # QQ.frac_field('x','y','z')
assert QQ.poly_ring('x','y').unify(ZZ.frac_field('x','z')) == EX # QQ.frac_field('x','y','z')
assert QQ.poly_ring('x','y').unify(QQ.frac_field('x','z')) == QQ.frac_field('x','y','z')
assert ZZ.frac_field('x').unify(ZZ.poly_ring('x')) == ZZ.frac_field('x')
assert ZZ.frac_field('x').unify(QQ.poly_ring('x')) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(ZZ.poly_ring('x')) == EX # QQ.frac_field('x')
assert QQ.frac_field('x').unify(QQ.poly_ring('x')) == QQ.frac_field('x')
assert ZZ.frac_field('x','y').unify(ZZ.poly_ring('x')) == ZZ.frac_field('x','y')
assert ZZ.frac_field('x','y').unify(QQ.poly_ring('x')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(ZZ.poly_ring('x')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x','y').unify(QQ.poly_ring('x')) == QQ.frac_field('x','y')
assert ZZ.frac_field('x').unify(ZZ.poly_ring('x','y')) == ZZ.frac_field('x','y')
assert ZZ.frac_field('x').unify(QQ.poly_ring('x','y')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(ZZ.poly_ring('x','y')) == EX # QQ.frac_field('x','y')
assert QQ.frac_field('x').unify(QQ.poly_ring('x','y')) == QQ.frac_field('x','y')
assert ZZ.frac_field('x','y').unify(ZZ.poly_ring('x','z')) == ZZ.frac_field('x','y','z')
assert ZZ.frac_field('x','y').unify(QQ.poly_ring('x','z')) == EX # QQ.frac_field('x','y','z')
assert QQ.frac_field('x','y').unify(ZZ.poly_ring('x','z')) == EX # QQ.frac_field('x','y','z')
assert QQ.frac_field('x','y').unify(QQ.poly_ring('x','z')) == QQ.frac_field('x','y','z')
raises(UnificationFailed, "ZZ.poly_ring('x','y').unify(ZZ, gens=('y', 'z'))")
raises(UnificationFailed, "ZZ.unify(ZZ.poly_ring('x','y'), gens=('y', 'z'))")
