LimitsPositioning

LimitsPositioning is an option for cells that determines whether or not to change the positioning of underscripts and overscripts in the way conventional for limits.

UnderoverscriptBox[x, y, z, LimitsPositioning False] is always displayed with explicit underscripts and overscripts, as .

UnderoverscriptBox[x, y, z, LimitsPositioning True] is displayed as when large, and when small.

The form is used when the box appears in a subscript or other script, or inline in a piece of text.

With the default setting LimitsPositioning->Automatic, the display of UnderoverscriptBox[x, y, z] depends on x. If x is \[Sum], \[Product] or another form conventionally displayed with limits, then LimitsPositioning->True is effectively used. Otherwise, LimitsPositioning->False is used.

LimitsPositioningTokens is a Cell option which can be set to a list of forms for which LimitsPositioning True should be used.

See The Mathematica Book: Section 2.9.11.

See also: LimitsPositioningTokens, ScriptSizeMultipliers.