!exists	macro	arg1,arg2
!	ifne	==arg2
!	move	arg1,arg2
!	elsec
!	push	arg1
!	endc
!	endm
!

!	exists	foo,bar
!	ifne	-1
!	move	foo,bar
	move	foo,bar
!	elsec
!	push	foo
!	endc
!	exists	foo
!	ifne	0
!	move	foo,
!	elsec
!	push	foo
	push	foo
!	endc
!