diff --git a/t/10-sets.t b/t/10-sets.t
index fc92d87..e53a706 100644
--- a/t/10-sets.t
+++ b/t/10-sets.t
@@ -10,16 +10,18 @@ use lib qw< t >;
 use ASTest;
 
 for my $test (test_specifications()) { # defined below
-   my ($t1, $op, $t2, $result) = @{$test}{qw< t1 op t2 result >};
+   my ($t1, $ops, $t2, $result) = @{$test}{qw< t1 op t2 result >};
    $t1 = locate_file($t1);
    $t2 = locate_file($t2);
-   {
-      my $res = sets_run($t1, $op, $t2);
-      is($res->{output}, $result, "$t1 $op $t2 - as separate items");
-   }
-   {
-      my $res = sets_run("$t1 $op $t2");
-      is($res->{output}, $result, "$t1 $op $t2 - as single string");
+   for my $op (ref $ops ? @$ops : $ops) {
+      {
+         my $res = sets_run($t1, $op, $t2);
+         is($res->{output}, $result, "$t1 $op $t2 - as separate items");
+      }
+      {
+         my $res = sets_run("$t1 $op $t2");
+         is($res->{output}, $result, "$t1 $op $t2 - as single string");
+      }
    }
 }
 
@@ -27,7 +29,7 @@ sub test_specifications {
    return (
       {
          t1 => 'lista1',
-         op => '-',
+         op => [qw< minus less \ - >],
          t2 => 'lista2',
          result => 'nono
 quarto
@@ -36,5 +38,37 @@ sesto
 ',
       },
 
+      {
+         t1 => 'lista1',
+         op => [qw< union u U v V | + >],
+         t2 => 'lista2',
+         result => 'ancora
+decimo
+nono
+nullo
+ottavo
+primo
+quarto
+quinto
+secondo
+sesto
+settimo
+terzo
+undicesimo
+',
+      },
+
+      {
+         t1 => 'lista1',
+         op => [qw< intersect i I & ^  >],
+         t2 => 'lista2',
+         result => 'decimo
+ottavo
+primo
+quinto
+settimo
+terzo
+',
+      },
    );
 }