/*****************************
add.lib
*****************************/

component { in opd1, opd2 } halfAdder { out sum, carry }
	begin
		{ in opd1 opd2 } xor( 2 ) { out sum };
		{ in opd1 opd2 } and( 2 ) { out carry };
	end
	
component { in opd1, opd2, carryIn } fullAdder { out sum, carryOut }
	begin
		path sum1, carry1, carry2;
		{ in opd1, opd2 } halfAdder { out sum1, carry1 };
		{ in sum1, carryIn } halfAdder { out sum, carry2 };
		{ in carry1 carry2 } or( 2 ) { out carryOut };
	end
	
component { in opd1[ n ], opd2[ n ], carryIn } add( n ) { out sum[ n ], carryOut }
	begin
		path carry[ n + 1 ];
		{ in carryIn } join( 1 ) { out carry[ 0 ] };
		for i from 0 upto n do
			{ in opd1[ i ], opd2[ i ], carry[ i ] } fullAdder 
				{ out sum[ i ], carry[ i + 1 ] };
		end
		{ in carry[ n ] } join( 1 ) { out carryOut };
	end