PRINT
INPUT PROMPT "引かれる２進数？ ":Q$
INPUT PROMPT "引く２進数？ ":W$
PRINT
LET QN=LEN(Q$)
LET WN=LEN(W$)
IF VAL(Q$)<VAL(W$) THEN
   LET P=QN
   LET QN=WN
   LET WN=P
   LET L$=Q$
   LET Q$=W$
   LET W$=L$
END IF
PRINT USING "###################":VAL(Q$)
PRINT USING "###################":VAL(W$)
PRINT "======================"
DIM A(20),B(20),C(20),Z(20)
MAT A=ZER
MAT B=ZER
MAT C=ZER
MAT Z=ZER

FOR i=1 TO QN
   LET A(i)=VAL(Q$(QN+1-i:QN+1-i))
NEXT i
FOR i=1 TO WN
   LET B(i)=VAL(W$(WN+1-i:WN+1-i))
NEXT i

FOR i=1 TO QN
   IF C(i)=O THEN
      IF XORA(A(i),B(i))=0 THEN
         LET Z(i)=0
      ELSE
         LET Z(i)=1
         IF A(i)=O THEN
            LET C(i+1)=1
         END IF
      END IF
   ELSE  ! C(i)=1 の場合
      IF A(i)=0 THEN
         LET A(i)=1
         LET C(i+1)=1
      ELSE
         LET A(i)=0
      END IF
      IF XORA(A(i),B(i))=0 THEN
         LET Z(i)=0
      ELSE   ! 一致しない場合
         LET Z(i)=1
         IF A(i)=O THEN
            LET C(i+1)=1
         END IF
      END IF
   END IF
NEXT i

LET R=0
FOR i=1 TO QN
   LET R=R+Z(i)*10^(i-1)
NEXT i
PRINT USING "###################":R+C(QN+1)*10^QN
PRINT
END

EXTERNAL FUNCTION ANDA(X,Y)
IF X=1 AND Y=1 THEN
   LET ANDA=1
ELSE
   LET ANDA=0
END IF
END FUNCTION

EXTERNAL FUNCTION ORA(X,Y)
IF X=0 AND Y=0 THEN
   LET ORA=0
ELSE
   LET ORA=1
END IF
END FUNCTION

EXTERNAL FUNCTION XORA(X,Y)
IF X=Y THEN
   LET XORA=0
ELSE
   LET XORA=1
END IF
END FUNCTION