ceil := q / (1 << bits)
			if diff > fieldElement(ceil) {
				t.Fatalf("decompress(compress(%d, %d), %d) = %d (diff %d, max diff %d)",
					a, bits, bits, got, diff, ceil)
			}
		}
	}
}

func CompressRat(x fieldElement, d uint8) uint16 {
	if x >= q {
		panic("x out of range")
	}
	if d <= 0 || d >= 12 {
		panic("d out of range")
	}

	precise := big.NewRat((1<<d)*int64(x), q) // (2ᵈ / q) * x == (2ᵈ * x) / q