// Adding

#define add_reversed_ALU(s0, s1, d) \
	from(rail, to, carry) [- \
						  from(carry, to, d) + \
						  from(d, to, s0) [- \
										  from(s0, to, d) - \
										  from(d, to, carry) \
										  previous_record + next_record \
										  from(carry, to, s1) [- \
															  from(s1, to, d) + from(d, to, s1) \
															  ] \
										  from(s1, to, s0) \
										  ] \
						  from(s0, to, s1) [- \
										   from(s1, to, d) - \
										   from(d, to, carry) \
										   previous_record + next_record \
										   from(carry, to, s1) \
										   ] \
						  from(s1, to, carry) \
						  ] \
	from(carry, to, s0) [- \
						from(s0, to, d) + \
						from(d, to, s1) [- \
										from(s1, to, d) - \
										from(d, to, carry) \
										previous_record + next_record \
										from(carry, to, s1) \
										] \
						from(s1, to, s0) \
						] \
	from(s0, to, s1) [- \
					 from(s1, to, d) + \
					 from(d, to, s1) \
					 ] \
	from(s1, to, rail) previous_record


// CLEARS s0 AND s1 !!!, carry and d must be cleared
#define add(s0, s1, d) \
	to_end previous_record \
	[ add_reversed_ALU(s0, s1, d) ]

#define add_to_ALU(s, d) \
	while(s, decrease(s) increase(d) ) \
	next_record

#define add_to_reversed_ALU(s, d) \
	while(s, decrease(s) increase(d) ) \
	previous_record

// CLEARS s !!!, d must be cleared
#define add_to(s, d) \
	next_record \
	[ add_to_ALU(s, d) ] \
	previous_record \
	[ normalize_reversed_ALU(d) ]

// CLEARS s !!!, d must be cleared
#define sub_of(s, d) \
	next_record \
	[ negate_ALU(s) ] \
	previous_record increase(d) \
	[ add_to_reversed_ALU(s, d) ] \
	next_record [ next_record ] previous_record \
	[ normalize_reversed_ALU(d) ] \
	decrease(d)
 
// NOT WORKING !!!
#define add_x(s0, s1, d) \
	next_record \
	[ add_x_ALU(s0, s1, d) ] \
	previous_record \
	[ normalize_reversed_ALU(d) ]

#define add_x_ALU(s0, s1, d) \
	while(carry, decrease(carry)) \
	if_signed(s0, then, increase(d) \
	if_signed(s1, then, increase(d) \
	next_record

// CLEARS s0 AND s1 !!!, carry and d must be cleared
#define subtract(s0, s1, d) \
	next_record \
	[ negate_ALU(s1) ] \
	previous_record \
	from(rail, to, carry) + from(carry, to, rail) \
	[ add_reversed_ALU(s0, s1, d) ]

// CLEARS s1 !!!, carry and d must be cleared, otherwise s0*s1 will be added to d
#define multiply(s0, s1, d) \
	fill_register(carry) \
	next_record \
	while(rail, \
		decrease(carry) \
		if_signed_x(s0, carry, then, \
			while(rail, \
				decrease(rail) \
				if_signed_x(s1, rail, then, increase(d) ) \
				increase(rail) \
				next_record \
			) \
			to_begin_of_carry \
		) \
		shift_right_on_carry(s1) \
		increase(carry) \
		next_record \
	) \
	previous_record [ normalize_reversed_ALU(d) ] \

#define normalize_reversed_ALU(n) \
	at(carry, clear) \
	decrease(rail) \
	while(n, \
		decrease(n) \
		increase(rail) \
		while(carry, \
			decrease(rail) \
			decrease(carry) \
			previous_record increase(n) next_record \
		) \
		while(rail, \
			decrease(rail) \
			increase(carry) \
		) \
	) \
	while(carry, \
		decrease(carry) \
		increase(n) \
	) \
	increase(rail)\
	previous_record