In the Simple Units environment, any verifications of valid dimensions ignore so-called Unit annotations.

In the Simple Units environment, the equality and inequality relators ($=,<,\le ,>,\ge$, and$\ne$) are modified so that they perform the necessary operations on expressions with units.

Every command in the Simple Units environment that needs to determine whether an expression is valid or not, does so using the Units[TestDimensions] command.

The properties of these relators are:

where $a$ and $b$ are units; $A$ and $B$ are coefficients; and $r$ is the conversion factor from the unit $b$ to the unit $a$.

To enter a unit in 2-D Math input, select the unit from the appropriate Units palette. If the unit you want is not there, select $\mathrm{unit}$ and then enter the unit.

When you edit a unit, double brackets appear around it.

$\mathrm{with}\left(\mathrm{Units}\left[\mathrm{Simple}\right]\right)\&colon;$

$3\mathrm{Unit}\left('\mathrm{ft}'\right)=\mathrm{Unit}\left('\mathrm{yd}'\right)$

$3=3$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$1.60\mathrm{Unit}\left('m'\right)<\mathrm{Unit}\left('\mathrm{mi}'\right)$

$1.60<\frac{201168}{125}$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$30.48\mathrm{Unit}\left('\mathrm{cm}'\right)=\mathrm{Unit}\left('\mathrm{ft}'\right)$

$30.48=\frac{762}{25}$

$\mathrm{evalb}\left(\right)$

$\mathrm{true}$

$3\mathrm{Unit}\left('\mathrm{ft}'\right)+3\mathrm{Unit}\left('\mathrm{inch}'\right)=\mathrm{Unit}\left('m'\right)$

$\frac{4953}{5000}=1$

$\mathrm{evalb}\left(\right)$

$\mathrm{false}$