You can include A4GL extensions in your program code and still compile the source with Informix 4GL compilers by enclosing A4GL specific statements within the delimiters {! and !}. Aubit4GL will ignore the {! and !} delimiters and compile the code enclosed. Informix 4GL compiles will see the {! and !} as no different syntactically from { and } and will therefore treat enclosed code as a comment (and therefore not try to compile it). This allows you to write functions like the following:

function isaubit()
   {! return true !}
   return false
end function