In operator notation, the element in parentheses can be considered a single coherent unit; fluid dynamics uses this convention extensively, terming it the convective derivative--the "moving" derivative of the fluid.
The element in parentheses can be considered a single coherent unit. This was in operator notation. Fluid dynamics uses this convention extensively,--the "moving" derivative of the fluid. Fluid dynamics are terming it the convective derivative--the ". Fluid dynamics are moving" derivative of the fluid.