PRINT
PRINT "原点を通る直線に関する鏡像"
PRINT 
INPUT PROMPT " χ，ｙ ":x,y
INPUT PROMPT "原点を通る直線の傾き  ":t
PRINT
LET a=-1/t
LET b=1/SQR(1+a^2)
DIM R(2,2)
LET R(1,1)=2*(a*b)^2-1
LET R(1,2)=-2*a*b*b
LET R(2,1)=-2*a*b*b
LET R(2,2)=1-2*(a*b)^2
DIM P(2)
LET P(1)=x
LET P(2)=y
DIM Q(2)
MAT Q=R*P
LET xx=ROUND(Q(1),4)
LET yy=ROUND(Q(2),4)
PRINT "(";xx;",";yy;")"
END