- (1.85): "F" has to be replaced by "L"
- (1.106): "F" has to be replaced by "L"
- (1.118): "G" has to be replaced by "L"
- (4.5): "-1.98" has to be replaced by "1.98"
- (5.36): "2x_1" has to be replaced by "-2x_1"