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.


my $bloop = -123;
 
if MY::{'$bloop'}.defined and CORE::{'&abs'}.defined { say abs $bloop }
 
my @ints = ($_ when Int for PROCESS::.values);
say "Number of PROCESS vars of type Int: ", +@ints;
say "PROCESS vars of type Int add up to ", [+] @ints;