Consider a vector field $\vec{A}(\vec{r}).$ The closed loop line integral $\displaystyle {} \int \vec{A}\bullet\vec{dl}$ can be expressed as
- $\displaystyle {} \iint (\triangledown \times \vec{A}) \bullet\vec{ds}$ over the closed surface bounded by the loop
- $\displaystyle {} \iiint (\triangledown \bullet \vec{A}) dv$ over the closed volume bounded by the loop
- $\displaystyle {} \iiint (\triangledown \bullet \vec{A}) dv$ over the open volume bounded by the loop
- $\displaystyle {} \iiint (\triangledown \times \vec{A}) \bullet\vec{ds}$ over the open surface bounded by the loop