Interesting... So what's wrong with this? sum_cubes2(1, 3) is returning 1 instead of 36 like it should and giving the warning "Use of uninitialized value in numeric gt (>) at /Users/mvaline/bin/summation line 35." 
sub sum {
    my ($term, $a, $next, $b) = @_;
    if ($a > $b) { return(0); }
    else { return( $term->($a) + &sum( $term, ($next->($a)), ($next->(
+$b)) ) ); }
}

sub inc {
    my ($n) = @_;
    return( $n + 1 );
}

sub sum_cubes2 {
    my ($a, $b) = @_;
    return( &sum(\&cube, $a, \&inc, $b) );
}

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In reply to Re: Re: Passing subroutines as arguments by mvaline
in thread Passing subroutines as arguments by mvaline

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