Autodoc mode is an additional minor-mode for automatically showing
information about symbols near the point. For function names the
argument list is displayed, and for global variables, the value.
Autodoc is implemented by means of
eldoc-mode of Emacs.
The mode can be enabled by default in your
(add-to-list 'slime-contribs 'slime-autodoc)
If the variable
slime-use-autodoc-mode is set (default), Emacs
starts a timer, otherwise the information is only displayed after
slime-autodoc-use-multiline-p is set to non-nil,
allow long autodoc messages to resize echo area display.