The Suppress command tells the Typesetting package to suppress the dependencies of a specified unknown function on display, and allow entry of that unknown function as just the function name on 2-D entry.

In addition, if Suppress is called with only the keyword query, it returns a set of all functions with dependency suppression currently enabled.

Only one suppression can be in effect at any time for a specific function name (e.g. you cannot suppress the dependencies of $f\left(t\right)$ and $f\left(x\,y\right)$ at the same time). In the event that Suppress is called for a function with a function name already having a suppression rule, the new function overrides the old.

Suppression is restricted to functions having a simple or indexed name (i.e. the function name must be of type 'name') and the dependencies must be of type 'name'). None of the dependencies can be repeated, and the dependencies cannot be the same as the function name. So, for example, the functions $f\left(\sin \left(x\right)\right)$, $f\left(x\,x\right)$, and $f\left(f\right)$ cannot be suppressed. In the event that an invalid function name is passed to Suppress a warning is issued.

The Unsuppress function simply disables dependency suppression for the specified functions (which for Unsuppress can be simply the name of the functions, or the actual functions).

In addition, if Unsuppress is called with only the keyword all, it then disables all dependency suppression currently in effect.

Dependency suppression interacts heavily with differentiation options in Settings (namely useprime, prime, usedot, dot and userep) to display and parse derivatives in a more aesthetic way.

In the following examples, we will assume that the settings for useprime and usedot are set to true, and the settings for prime and dot are the names $x$ and $t$, respectively.

And with userep set to true we get:

Note that userep has no effect unless the function dependencies are also suppressed.

Note that setting and querying of function suppression can also be performed in the Dependency Suppression area of the interactive Typesetting Assistant.

$\mathrm{with}\left(\mathrm{Typesetting}\right)\:$

$\mathrm{Suppress}\left(f\left(x\right)\right)$

$\mathrm{Suppress}\left(f\left(x\,y\right)\right)$

Warning, depencency for function f has been overridden

$\mathrm{Suppress}\left(\left\{g\left(x\,y\right)\,h\left(x\,y\right)\,y\left(y\right)\,f\left[1\right]\left(x\right)\right\}\right)$

Warning, function cannot have the same name as an argument, ignored y(y)

$\mathrm{Suppress}\left(\mathrm{query}\right)$

$\left\{f\,g\,h\,f_1\right\}$

$\mathrm{Unsuppress}\left(f\right)$

$\mathrm{Suppress}\left(\mathrm{query}\right)$

$\left\{g\,h\,f_1\right\}$

$\mathrm{Unsuppress}\left(\mathrm{all}\right)$

$\mathrm{Suppress}\left(\mathrm{query}\right)$

$\varnothing$