Adjective
superadditive (not comparable)
(mathematics, of a function) Such that the image of a sum is at least the sum of the images of the summands.
Knot genus is superadditive under band sum because
g
(
K
1
♯
b
K
2
)
≥
g
(
K
1
)
+
g
(
K
2
)
{\displaystyle g(K_{1}\sharp _{b}K_{2})\geq g(K_{1})+g(K_{2})}
.