Minus.diff

diff --git a/src/core/set_operators.pm b/src/core/set_operators.pm
index aaf654e..d3fa24e 100644
--- a/src/core/set_operators.pm
+++ b/src/core/set_operators.pm
@@ -123,13 +123,13 @@ only sub infix:<(-)>(**@p) {
         }
         $baghash.Bag(:view);
     } else {
-        my $sethash = nqp::istype(@p[0],SetHash)
-          ?? SetHash.new(@p.shift.keys)
-          !! @p.shift.SetHash;
-        for @p.map(*.Set(:view)) -> $set {
-            $set{$_} && $sethash.DELETE-KEY($_) for $sethash.keys;
-        }
-        $sethash.Set(:view);
+        my $start-set = @p.shift.Set(:view);
+        my $minus-set = @p == 1
+            ?? @p[0].Set(:view)
+            !! Set.new(eager @p.map(*.Set(:view).keys));
+        Set.new(eager $start-set.keys.grep: {
+            not $minus-set{$_}
+        });
     }
 }
 # U+2216 SET MINUS