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.


      IF VAL(FNversion) < 5.94 THEN PRINT "Version is too old" : END
 
      ON ERROR LOCAL PRINT "Variable 'bloop' doesn't exist" : END
      test = bloop
      RESTORE ERROR
 
      ON ERROR LOCAL PRINT "Function 'FNabs()' is not defined" : END
      test = ^FNabs()
      RESTORE ERROR
 
      PRINT FNabs(bloop)
      END
 
      DEF FNversion
      LOCAL F%, V$
      F% = OPENOUT(@tmp$+"version.txt")
      OSCLI "OUTPUT "+STR$F%
      *HELP
      *OUTPUT 0
      PTR #F% = 0
      INPUT #F%,V$
      CLOSE #F%
      = RIGHT$(V$,5)