24 lines
618 B
Perl
24 lines
618 B
Perl
|
:- module(adder,[sum/3]).
|
||
|
|
|
||
|
|
sum([B],[S],(S==B)).
|
||
|
|
sum([B1,B2|Bs],Sum,F1*F2*F3) :-
|
||
|
|
split([B1,B2|Bs],Xs,Ys),
|
||
|
|
sum(Xs,S1,F1), sum(Ys,S2,F2),add(S1,S2,Sum,F3).
|
||
|
|
|
||
|
|
split([],[],[]).
|
||
|
|
split([X],[X],[0]).
|
||
|
|
split([X,Y|XYs],[X|Xs],[Y|Ys]) :- split(XYs,Xs,Ys).
|
||
|
|
|
||
|
|
add([X|Xs],[Y|Ys],[Z|Zs],(Z==SumXY)*Sum) :-
|
||
|
|
halfadder(X,Y,SumXY,CarryXY),
|
||
|
|
adder(Xs,Ys,CarryXY,Zs,Sum).
|
||
|
|
|
||
|
|
adder([],[],Carry,[Z],Z==Carry).
|
||
|
|
adder([X|Xs],[Y|Ys],Carry,[Z|Zs],(Z==SumXY)*Rest) :-
|
||
|
|
fulladder(X,Y,Carry,SumXY,CarryXY),
|
||
|
|
adder(Xs,Ys,CarryXY,Zs,Rest).
|
||
|
|
|
||
|
|
fulladder(X, Y, C, (X xor Y xor C), (C->(X+Y);(X*Y)) ).
|
||
|
|
halfadder(X, Y, (X xor Y), X*Y ).
|
||
|
|
|