[235]> (setf f #'abs)               ; I'm ok with this
#<SYSTEM-FUNCTION ABS>

[236]> (abs 3)                      ; This is fine
3

[237]> (f 3)                        ; Err due to sep. fn namespace. OK.

-- Err[1]: "Undefined function f" --

[238]> (#'f 3)                      ; Don't get what this err is telling me...
-- Err[2]: "#'F is not a function name, try using a symbol instead"

[239]> (funcall #'f 3)              ; seems very long winded...!
3

CL-USER 54 > (defvar foo 3)
FOO

CL-USER 55 > (defun foo (x) (* foo 10))
FOO

CL-USER 56 > (foo foo)
30

CL-USER 57 > (fdefinition 'foo)
#<interpreted function FOO 4060001CAC>

CL-USER 58 > (symbol-function 'foo)
#<interpreted function FOO 4060001CAC>

CL-USER 58a > #'foo
#<interpreted function FOO 4060001CAC>

CL-USER 59 > (function foo)            ; works also for local functions
#<interpreted function FOO 4230008AAC>

CL-USER 60 > (symbol-value 'foo)
3

CL-USER 61 > foo
3