where formula_9 and formula_10; note that the superscript formula_11 should not be interpreted as an exponent, it is merely another index. when the number of terms formula_6 is minimal in the above expression, then formula_6 is called the rank of the tensor, and the decomposition is often referred to as a "(tensor) rank decomposition", "minimal cp decomposition", or "canonical polyadic decomposition (cpd)". contrariwise, if the number of terms is not minimal, then the above decomposition is often referred to as "formula_6-term decomposition", "candecomp/parafac" or "polyadic decomposition".