|cons creates a cons cell, acons tests if it is a cons|
list creates a list, alist tests if it is a list
sym creates a symbol
string creates a string
but... number tests if it is a number
for the "arithmetical plus" I mentioned in http://arclanguage.org/item?id=3601, I said, oh, I'd want a function "number" that converts its argument to a number...
however that would require renaming number to something else like anumber... which would also be consistent with the naming of acons and alist.
(def number (x)
(if (no x) 0 (coerce x 'int)))