Task

 verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
 check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).


Extra credit

 Report the number of integer variables in global scope, and their sum.


' FB 1.05.0 Win64
 
#If __FB_VERSION__ < "1.06.0"
  #Error "Compiler version is too old - needs to be 1.06.0 or later"
#EndIf
 
Dim bloop As Integer = -15
#IfDef bloop
  #IfDef Abs
    Print "Abs(bloop) = "; Abs(bloop)
  #Else
    Print "Abs is not available"
  #EndIf
#Else
  Print "bloop does not exist"
#EndIf 
Sleep