-----Athanasios Anastasiou <athanastasiou at googlemail.com> wrote: -----
>As?i?said?before,?i?am?taking?my?first?steps?in?Maxima,?so?i?can?not?help
>it?not?to?ask?if?the?trick?was?done?by?the?''?or?the?parentheses?:-D?.?I
>thought?it?was?because?of?the?parentheses?which?would?"force"?the
>expression?in?them?to?be?evaluated?first,?but?the?two?accents?('')?seem?to
>be?required?as?well.?(?)
>From the user documentation for quote-quote:
"The quote-quote operator is applied by the input parser; it is not stored
as part of a parsed input expression. The quote-quote operator is always
applied as soon as it is parsed, and cannot be quoted. Thus quote-quote
causes evaluation when evaluation is otherwise suppressed, such as in
function definitions, lambda expressions, and expressions quoted by single
quote '."
Also:
(%i36) f(x) := 45;
(%o36) f(x):=45
(%i37) lsum(f(x),x,l);
(%o37) lsum(f(x),x,l)
Apply quote-quote to entire expression f(x):
(%i39) lsum(''(f(x)),x,l);
(%o39) lsum(45,x,l)
Apply quote-quote to just f:
(%i40) lsum(''f(x),x,l);
(%o40) lsum(f(x),x,l)
Barton