31.11. Additional Fancy Macros and Functions  31.11.1. Macro
EXT:ETHE 31.11.2. Macros EXT:LETF & EXT:LETF* 31.11.3. Macro
EXT:MEMOIZED 31.11.4. Macro EXT:WITH-COLLECT 31.11.6. Macro
EXT:WITH-GENSYMS 31.11.7. Function EXT:REMOVE-PLIST 31.11.9.
Function EXT:OPEN-HTTP and macro EXT:WITH-HTTP-INPUT 31.11.10.
Variable CUSTOM:*HTTP-LOG-STREAM* 31.11.11. Function EXT:BROWSE-
URL 31.11.12. Variable CUSTOM:*HTTP-PROXY* 31.11.13. Function
EXT:CANONICALIZE  CLISP comes with some extension macros, mostly
defined in the file macros3.lisp and loaded from the file
init.lisp during make:  31.11.1. Macro EXT:ETHE  (EXT:ETHE
value-type form) enforces a type check in both interpreted and
compiled code.  31.11.2. Macros EXT:LETF & EXT:LETF*  These
macros are similar to LET and LET*, respectively, except that
they can bind places, even places with multiple values. Example:
(letf (((values a b) form)) ...)  is equivalent to  (multiple-
value-bind (a b) form ...)   (letf (((first l) 7)) ...)  is
approximately equivalent to   (LET* (