View Compilation Error

0_0_12352502_3573.cpp: In member function `void IntervalTree::pushdown(int)':
0_0_12352502_3573.cpp:34: error: `l' undeclared (first use this function)
0_0_12352502_3573.cpp:34: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12352502_3573.cpp:34: error: `r' undeclared (first use this function)