The where function displays the stack of procedure activations. Starting at the top level, it shows the statement being executed, and the actual parameters passed to the called procedure.

If numLevels is specified, only that many bottommost activations are displayed.

The where function is generally called from within a procedure for debugging purposes. The intent is to be able to determine from where a procedure is being called.

The debugger has a where command which is analogous to the Maple where function, except that it can be invoked interactively by the user from the debugger command line.

$\mathrm{where}\left(\right)$

Currently at TopLevel.

f := proc(x) g(args) end proc:

g := proc(x) h(args) end proc:

h := proc(x) j(args) end proc:

j := proc(x) where(args) end proc:

$f\left(\right)$

TopLevel: f()
        []
f: g(_passed)
        []
g: h(_passed)
        []
h: j(_passed)
        []
Currently in j.

$f\left(3\right)$

g: h(_passed)
        [3]
h: j(_passed)
        [3]
Currently in j.