Implement IF, THE and FUNCTION for lexical functions.
Implement IF, THE and FUNCTION for lexical functions.

AugustusHuang/Mezzano,froggey/Mezzano,froggey/Mezzano,AugustusHuang/Mezzano,varjagg/Mezzano,rvedam/Mezzano,varjagg/Mezzano,rvedam/Mezzano