>

t := proc() Digits := Digits + 4; end proc:

>

$\mathrm{print}\left(\mathrm{Digits}\right)$

During the execution of "t", Digits is increased by 4, and automatically reset on exit from "t".
>

$\mathrm{print}\left(\mathrm{Digits}\right)$

The following is an example of a userdefined environment variable.
>

$\mathrm{\_Envy}\u2254\mathrm{foo}$

${\mathrm{\_Envy}}{\u2254}{\mathrm{foo}}$
 (4) 
>

p := proc() _Envy := bar end proc:

>

$\mathrm{anames}\left(\mathrm{environment}\right)$

${\mathrm{Testzero}}{\,}{\mathrm{UseHardwareFloats}}{\,}{\mathrm{Rounding}}{\,}{\%}{\,}{\mathrm{\_ans}}{\,}{\mathrm{\%\%\%}}{\,}{\mathrm{Digits}}{\,}{\mathrm{index/newtable}}{\,}{\mathrm{mod}}{\,}{\mathrm{\%\%}}{\,}{\mathrm{Order}}{\,}{\mathrm{printlevel}}{\,}{\mathrm{Normalizer}}{\,}{\mathrm{NumericEventHandlers}}{\,}{\mathrm{\_Envy}}$
 (7) 
>

p := proc() _Envy := bar; anames(environment) end proc:

${\mathrm{Testzero}}{\,}{\mathrm{UseHardwareFloats}}{\,}{\mathrm{Rounding}}{\,}{\%}{\,}{\mathrm{\_ans}}{\,}{\mathrm{\%\%\%}}{\,}{\mathrm{Digits}}{\,}{\mathrm{index/newtable}}{\,}{\mathrm{mod}}{\,}{\mathrm{\%\%}}{\,}{\mathrm{Order}}{\,}{\mathrm{printlevel}}{\,}{\mathrm{Normalizer}}{\,}{\mathrm{NumericEventHandlers}}{\,}{\mathrm{\_Envy}}{\,}{\mathrm{\_Envy}}$
 (8) 