∫ ∬ ∭ ∮ ∯ ∰
/ /
∬ … ∫ D f ( x 1 , x 2 , … , x n ) d x 1 d x 2 … d x n {\displaystyle \iint \ldots \int _{\mathbf {D} }\;f(x_{1},x_{2},\ldots ,x_{n})\;\mathbf {d} x_{1}\mathbf {d} x_{2}\!\ldots \mathbf {d} x_{n}}
w t f ? {\displaystyle wtf?}