inferior-lisp-prompt

inferior-lisp-prompt is a variable defined in `inf-lisp.el'.
Its value is

"^[^> 
]*>+:? *"

Documentation:
Regexp to recognize prompts in the Inferior Lisp mode.
Defaults to "^[^> \n]*>+:? *", which works pretty good for Lucid, kcl,
and franz. This variable is used to initialize `comint-prompt-regexp' in the
Inferior Lisp buffer.

This variable is only used if the variable
`comint-use-prompt-regexp' is non-nil.

More precise choices:
Lucid Common Lisp: "^\\(>\\|\\(->\\)+\\) *"
franz: "^\\(->\\|<[0-9]*>:\\) *"
kcl: "^>+ *"

You can customize this variable.