Teach Units(GF(q)) its size

gap-system · Mar 1, 2018 · ad6bb49 · ad6bb49
1 parent abe1a58
commit ad6bb49
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/lib/fieldfin.gi b/lib/fieldfin.gi
@@ -79,7 +79,14 @@ InstallMethodWithRandomSource( Random,
 InstallMethod( Units,
     "for a finite field",
     [ IsField and IsFinite ],
-    F -> GroupByGenerators( [ PrimitiveRoot( F ) ] ) );
+    function ( F )
+    local G;
+    G := GroupByGenerators( [ PrimitiveRoot( F ) ] );
+    if HasSize( F ) then
+      SetSize( G, Size( F )-1 );
+    fi;
+    return G;
+    end );
 
 
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