View Compilation Error

0_0_10722383_30264.c: In function `Isprime':
0_0_10722383_30264.c:16: error: `true' undeclared (first use in this function)
0_0_10722383_30264.c:16: error: (Each undeclared identifier is reported only once
0_0_10722383_30264.c:16: error: for each function it appears in.)
0_0_10722383_30264.c:20: error: `false' undeclared (first use in this function)