View Compilation Error

0_0_33164399_27401.cpp: In function 'bool isCross(Line, Line)':
0_0_33164399_27401.cpp:67:9: error: 'L2' was not declared in this scope
  mu1 = (L2.x1 - L1.x1) * (L1.y2 - L1.y1) - (L1.x2 - L1.x1) * (L2.y1 - L1.y1);
         ^
0_0_33164399_27401.cpp:67:17: error: 'L1' was not declared in this scope
  mu1 = (L2.x1 - L1.x1) * (L1.y2 - L1.y1) - (L1.x2 - L1.x1) * (L2.y1 - L1.y1);
                 ^