Data commit

Task/Four-bit-adder/PicoLisp/four-bit-adder.l

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+(de halfAdder (A B)  #> (Carry . Sum)
+   (cons
+      (and A B)
+      (xor A B) ) )
+
+(de fullAdder (A B C)  #> (Carry . Sum)
+   (let (Ha1 (halfAdder C A)  Ha2 (halfAdder (cdr Ha1) B))
+      (cons
+         (or (car Ha1) (car Ha2))
+         (cdr Ha2) ) ) )
+
+(de 4bitsAdder (A4 A3 A2 A1  B4 B3 B2 B1)  #> (V S4 S3 S2 S1)
+   (let
+      (Fa1 (fullAdder A1 B1)
+         Fa2 (fullAdder A2 B2 (car Fa1))
+         Fa3 (fullAdder A3 B3 (car Fa2))
+         Fa4 (fullAdder A4 B4 (car Fa3)) )
+      (list
+         (car Fa4)
+         (cdr Fa4)
+         (cdr Fa3)
+         (cdr Fa2)
+         (cdr Fa1) ) ) )