@defun "add2" {
	"y2" store
	"x2" store
	"y1" store
	"x1" store
	x1 x2 +
	y1 y2 +
}

@defun "diff2" {
	"y2" store
	"x2" store
	"y1" store
	"x1" store
	x1 x2 -
	y1 y2 -
}

@defun "dup2" {
	"b" store
	"a" store
	a b a b
}

@defun "dup4" {
	"d" store
	"c" store
	"b" store
	"a" store
	a b c d a b c d
}

@defun "swap2" {
	"b2" store
	"b1" store
	"a2" store
	"a1" store
	b1 b2 a1 a2
}

@defun "replicate" { #args: value times
	dup 1 < if
		pop pop
	else
		1 - "t" store
		t 0 > while
			dup
			t 1 - "t" store
		t 0 > end
	end
}