I am working on arm controller and am using stm32103EXL. When i try to build my project errors and warnings are displayed in my header files. But those errors are shown only in my project. If i try to use those header files for a different project it doesnt pose any pblm.. Please tell me a solution as soon as posssible.Rebuild target 'STM32F103 Flash' assembling startup_stm32f10x_hd.s... compiling system_stm32f10x.c... compiling GLCD_16bitIF_STM32.c... compiling LED.c... compiling ADC.c... compiling IRQ.c... compiling Serial.c... compiling Retarget.c... compiling Blinky.c... complex.h(98): warning: #223-D: function "sqrt" declared implicitly complex.h(105): warning: #223-D: function "atan" declared implicitly complex.h(112): warning: #223-D: function "cos" declared implicitly complex.h(113): warning: #223-D: function "sin" declared implicitly C:\Keil\ARM\ARMCC\bin\..\include\math.h(238): error: #159: declaration is incompatible with previous "atan" (declared at line 105 of "complex.h") C:\Keil\ARM\ARMCC\bin\..\include\math.h(248): error: #159: declaration is incompatible with previous "cos" (declared at line 112 of "complex.h") C:\Keil\ARM\ARMCC\bin\..\include\math.h(253): error: #159: declaration is incompatible with previous "sin" (declared at line 113 of "complex.h") C:\Keil\ARM\ARMCC\bin\..\include\math.h(328): error: #159: declaration is incompatible with previous "sqrt" (declared at line 98 of "complex.h") Target not created