Language: C C++ D Haskell Lua OCaml PHP Perl Plain Text Python Ruby Scheme Tcl ; triangle roll-up (define (but-last xs) (reverse (cdr (reverse xs)))) (define (pair-wise f xs) (map f (but-last xs) (cdr xs))) (define (roll-up xs) (when (pair? xs) (roll-up (pair-wise + xs)) (display xs) (newline))) (roll-up '(4 7 3 6 7)) Private [?] Run code Submit