TitsGroupT[] represents the simple Tits group T.
TriangleWave[x] gives a triangle wave that varies between -1 and +1 with the unit period.TriangleWave[{min, max}, x] gives a triangle wave that varies between min and max ...
UnionPlus[x, y, ...] displays as x \[UnionPlus] y \[UnionPlus] ....
UnitBox
(Built-in Mathematica Symbol) UnitBox[x] represents the unit box function, equal to 1 for |x| <= 1/2 and 0 otherwise.UnitBox[x_1, x_2, ...] represents the multidimensional unit box function, equal to 1 if ...
UnsavedVariables is an option for Manipulate, DynamicModule, and related functions that specifies local symbols that should not be saved when the notebook containing them is ...
UpArrowBar[x, y, ...] displays as x\[UpArrowBar]y\[UpArrowBar]....
UpArrowDownArrow[x, y, ...] displays as x\[UpArrowDownArrow]y\[UpArrowDownArrow]....
UpArrow
(Built-in Mathematica Symbol) UpArrow[x, y, ...] displays as x\[UpArrow]y\[UpArrow]TraditionalForm\`....
UpDownArrow[x, y, ...] displays as x\[UpDownArrow]y\[UpDownArrow]....
UpEquilibrium[x, y, ...] displays as x\[UpEquilibrium]y\[UpEquilibrium]....