USE: fry : make-query ( string -- quot ) '[ 1 swap nth _ swap subseq? ] ; : na? ( array -- ? ) "na" make-query ; ! sample date from a CSV file { "id" "fname" "lname" "age" } na? ! I get the following error ! The word na? cannot be executed because it failed to compile ! Stack effect declaration is wrong ! inferred ( -- x ) ! declared ( array -- ? )