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

In the Simple Units environment, the frem procedure overrides the top-level frem procedures. The units for the arguments need to have the same dimension, and the result is given a unit corresponding to that dimension.

More precisely, if x1 and x2 have the same unit, then the result has that unit. If they have different units of the same dimension, then the result has the default unit for that dimension (as set by the UseUnit or UseSystem commands).

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.

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.

$\mathrm{with}\left(\mathrm{Units}\left[\mathrm{Simple}\right]\right)\:$

$\mathrm{frem}\left(\frac{3}{2}\mathrm{Unit}\left('m'\right)\,1.49\mathrm{Unit}\left('m'\right)\right)$

$0.010000000⟦m⟧$

$\mathrm{frem}\left(\frac{3}{2}\mathrm{Unit}\left('\mathrm{ft}'\right)\,1.49\mathrm{Unit}\left('\mathrm{ft}'\right)\right)$

$0.010000000⟦\mathrm{ft}⟧$

$\mathrm{frem}\left(\frac{3}{2}\mathrm{Unit}\left('m'\right)\,1.49\mathrm{Unit}\left('\mathrm{ft}'\right)\right)$

$0.137544000⟦m⟧$

The Units[Simple][frem] command was introduced in Maple 2021.

For more information on Maple 2021 changes, see Updates in Maple 2021.