View Compilation Error

0_0_5580007_7528.c: In function `main':
0_0_5580007_7528.c:5: error: `bool' undeclared (first use in this function)
0_0_5580007_7528.c:5: error: (Each undeclared identifier is reported only once
0_0_5580007_7528.c:5: error: for each function it appears in.)
0_0_5580007_7528.c:5: error: syntax error before "fun_c"
0_0_5580007_7528.c:8: error: syntax error before "flag"
0_0_5580007_7528.c:11: error: `flag' undeclared (first use in this function)
0_0_5580007_7528.c:13: error: `true' undeclared (first use in this function)
0_0_5580007_7528.c: At top level:
0_0_5580007_7528.c:29: error: syntax error before "fun_c"
0_0_5580007_7528.c: In function `fun_c':
0_0_5580007_7528.c:36: error: `true' undeclared (first use in this function)
0_0_5580007_7528.c:37: error: `false' undeclared (first use in this function)