View Compilation Error

0_0_33159513_15594.cpp: In function 'bool Geo_2D::segment_proper_intersection(Geo_2D::Point, Geo_2D::Point, Geo_2D::Point, Geo_2D::Point)':
0_0_33159513_15594.cpp:124:31: error: invalid operands of types 'double' and 'int' to binary 'operator%'
  double c1=cross(a2-a1,b1-a1)%2
                               ^
0_0_33159513_15594.cpp:124:31: error: expected ',' or ';' at end of input
0_0_33159513_15594.cpp:124:31: error: expected '}' at end of input
0_0_33159513_15594.cpp: At global scope:
0_0_33159513_15594.cpp:124:31: error: expected '}' at end of input