quot; Sometimes it is written "Let $\star=\frac{22}{7}$, or using a proper assignment symbol like one of the following: $\star \leftarrow \frac{22}{7}$ $\star := \frac{22}{7}$ $\star \overset{\text{def}}= \frac{22}{7}$ In a sense, this makes the symbol ($\star$ in this case) ditch all of its previous meanings to take on the new role as short hand for whatever it was **assigned**. The symbol can then be used in place of the mathematical object. $7\star=22$