TooltipDelay is an option for objects such as Tooltip that specifies how long to delay after the mouse is over the object before displaying the tooltip.

Tooltip[expr, label] displays label as a tooltip while the mouse pointer is in the area where expr is displayed.

TopHatTransform[image, ker] gives the morphological top-hat transform of image with respect to structuring element ker.TopHatTransform[image, r] gives the top-hat transform ...

Top is a symbol that represents the top for purposes of alignment and positioning.

TopologicalSort[g] gives a list of vertices of g in topologically sorted order for a directed acyclic graph g.

ToRadicals[expr] attempts to express all Root objects in expr in terms of radicals.

ToRules[eqns] takes logical combinations of equations, in the form generated by Roots and Reduce, and converts them to lists of rules, of the form produced by Solve.

ToString[expr] gives a string corresponding to the printed form of expr in OutputForm. ToString[expr, form] gives the string corresponding to output in the specified form.

Total[list] gives the total of the elements in list. Total[list, n] totals all elements down to level n. Total[list, {n}] totals elements at level n. Total[list, {n_1, n_2}] ...

TotalVariationFilter[image] iteratively reduces noise while preserving edges in image.TotalVariationFilter[image, param] assumes a regularization parameter value param.