import scas.base.
import scas.polynomial.tree.MultivariatePolynomial
import .given

val r = MultivariatePolynomial.withSubresGCD()("x")
val x = r.generators
import r.{gcd, given}

assert (gcd(0, 0) >< 0)
assert (gcd(x, 0) >< x)
assert (gcd(1, x) >< 1)
assert (gcd((1x)*(1x), (1x)*(1x)) >< 1x)