doc: cookbook: Mention common SRFI-1 procedures.

* doc/guix-cookbook.texi (A Scheme Crash Course): Add item about
SRFI-1.

doc/guix-cookbook.texi

@@ -192,7 +192,8 @@ rest are the arguments passed to the function.  Every function returns the
 last evaluated expression as its return value.
 
 @item
-Anonymous functions are declared with the @code{lambda} term:
+Anonymous functions---@dfn{procedures} in Scheme parlance---are declared
+with the @code{lambda} term:
 
 @lisp
 (lambda (x) (* x x))
@@ -208,6 +209,9 @@ which can in turn be applied to an argument:
 @result{} 9
 @end lisp
 
+Procedures are regular values just like numbers, strings, Booleans, and
+so on.
+
 @item
 Anything can be assigned a global name with @code{define}:
 
@@ -233,6 +237,30 @@ A list structure can be created with the @code{list} procedure:
 @result{} (2 3 5 7)
 @end lisp
 
+@item
+Standard procedures are provided by the @code{(srfi srfi-1)} module to
+create and process lists (@pxref{SRFI-1, list processing,, guile, GNU
+Guile Reference Manual}).  Here are some of the most useful ones in
+action:
+
+@lisp
+(use-modules (srfi srfi-1))  ;import list processing procedures
+
+(append (list 1 2) (list 3 4))
+@result{} (1 2 3 4)
+
+(map (lambda (x) (* x x)) (list 1 2 3 4))
+@result{} (1 4 9 16)
+
+(delete 3 (list 1 2 3 4))        @result{} (1 2 4)
+(filter odd? (list 1 2 3 4))     @result{} (1 3)
+(remove even? (list 1 2 3 4))    @result{} (1 3)
+(find number? (list "a" 42 "b")) @result{} 42
+@end lisp
+
+Notice how the first argument to @code{map}, @code{filter},
+@code{remove}, and @code{find} is a procedure!
+
 @item
 @cindex S-expression
 The @dfn{quote} disables evaluation of a parenthesized expression, also