relational macros

# This seems over complex and I'm not sure if it is complete;
# what is the minimum necessary?

def add(a>, b<, c<)
	a = b + c
def add(a<, b>, c<)
	b = a - c
def add(a<, b<, c>)
	add(a, c, b)

def add(a>)
	a = 0
def add(a, b, ...)
	add(x, ...)
	add(a, b, x)