want to read the demo project's retire source in IAR IDE, but some functions' definition cannot be found?

 I’m learning programming for RL78/G13. I use ‘Demo Kit for RL78G13’ ( PN: YRDKRL78G13). After install ‘IAR Embedded workbench IDE’, I can open the project of ‘ADC_OneShot-Debug’. I move down the mouse and open the Applilet Code, and then saw all source code ( .c file and .h file) there. I open r_main.c to read.

I want to read entire source, but some functions’ definition cannot be found. E.g.    ( Under r_main.c)  LCDStringLinePos( ), etc, etc.    may I know where I can find their definition?  Thanks a lot