Ideas for features to be added in the future

; idea.1 $0 in function definition
{$0!}! ; infinite loop
       ; $0 returns the innermost lambda
	   ; can't think of any use cases

; idea.2 differential
5 $f ' !
{$1 2 ^} ' ; return {$1 2 *}
6 {$1 2 ^} ' ! ; return 12

; idea.3 integral
5 $f S !
{$1 2 ^} S ; return {$1 3 ^ 3 /}
6 {$1 2 ^} S ! ; return 72

; idea.4 variables
; not registers, but something more mathematical
; for equation solver and such

; idea.5 IR
; convert to IR before evaluating

; idea.6 continuation
; #1
5 6 + 4 @c 9 +  ; @c returns {$1 9 +} and exit
				; need to figure out how to eval continuation
                ; ans (top of the stack, lambda not evaluated): {$1 9 +}
; #2
{5 6 + 4 $1!} @c 9 + ; like call/cc
                     ; @c takes one lambda expression as an argument and passes
					 ; continuation as the argument of the lambda expression

; idea.7 log-axis graph

; idea.8 validate command

; idea.9 multi valued return if rsp != rbp