prints expr using the appropriate combination of the specified unit display forms forms.
- The following unit display forms can be specified: "Abbreviation", "LongForm".
- "SingularForm" can be included as a display form specification to force "LongForm" descriptions to their singular tense.
- If expr is a canonical unit, QuantityForm will print with the specified form of the unit.
- QuantityForm acts as a "wrapper", which affects printing, but not evaluation.
Introduced in 2012