Active and Inert Functions - Maple Help

Active and Inert Functions

 Some Maple commands have both active and inert forms. The command names are the same except for the case of the first letter. The active forms start with a lowercase letter and immediately compute a result. The inert forms start with an uppercase letter and are useful to show steps in the problem-solving process.
 Inert functions have other uses in Maple. For example, inert functions are used together with the mod operator to perform modular arithmetic over finite rings and fields.  For more information, see mod.
 These are some of the Maple commands that have both active and inert forms:
 • diff (Diff)
 • int (Int)
 • limit (Limit)
 •
 • product (Product)
 • sum (Sum)
 In the Standard interface, Maple displays inert forms in gray so they are easily distinguished from the active forms of the same commands.
 > int(x^2,x);
 $\frac{{{x}}^{{3}}}{{3}}$ (1)
 > Int(x^2,x);
 ${\int }{{x}}^{{2}}\phantom{\rule[-0.0ex]{0.3em}{0.0ex}}{ⅆ}{x}$ (2)
 You can also make any Maple function inert by prefixing it with the % symbol.  For more information, see the value help page.