PRINT
PRINT "y=ax+b と y=cx+d の交点を求める"
PRINT
INPUT PROMPT "my=ax+b: m,a,b? ":m,a,b
INPUT PROMPT "ny=cx+d: n,c,d? ":n,c,d
PRINT
DIM S(2,2),T(2,2),W(2,2),R(2,2)
LET S(1,1)=-1*a
LET S(1,2)=m
LET S(2,1)=-1*c
LET S(2,2)=n
LET T(1,1)=b
LET T(1,2)=b
LET T(2,1)=d
LET T(2,2)=d
PRINT "行列Ｓ："
CALL GYRE1(S)
PRINT "行列Ｔ："
CALL GYRE1(T)
IF S(1,1)*S(2,2)-S(1,2)*S(2,1)=0 THEN
   PRINT "２つの直線は交わりません。"
   GOTO 10
END IF
MAT W=INV(S)
MAT R=W*T
PRINT "Ｓの逆行列："
CALL GYRE2(W)
PRINT "Ｓの逆行列 × 行列Ｔ："
CALL GYRE2(R)
PRINT "２つの直線の交点："
PRINT "   x ＝ ";ROUND(R(1,1),3)
PRINT "   y ＝ ";ROUND(R(2,1),3)
10 PRINT
END

EXTERNAL SUB GYRE1(Q(,))
   FOR i=1 TO 2
      FOR j=1 TO 2
         PRINT USING "####":Q(i,j);
      NEXT j
      PRINT
   NEXT i
   PRINT
END SUB

EXTERNAL SUB GYRE2(Q(,))
   FOR i=1 TO 2
      FOR j=1 TO 2
         PRINT USING "####.###":ROUND(Q(i,j),3);
      NEXT j
      PRINT
   NEXT i
   PRINT
END SUB