Fix a small error in doc.

Packages/Visibility_complex/doc_tex/Visibility_complex_ref/VisibilityComplexFace.tex

@@ -58,10 +58,10 @@ The concept \ccRefName\ defines the requirements for the \ccc{Face} type in the
 \ccOperations
 
 \ccTagFullDeclarations
-\ccMethod{Edge_handle sup(); const}
+\ccMethod{Vertex_handle sup(); const}
     {returns the sink of face \ccVar.}
 \ccGlue
-\ccMethod{Edge_handle inf(); const}
+\ccMethod{Vertex_handle inf(); const}
     {returns the source of face \ccVar.}
 \ccGlue
 \ccMethod{void set_sup(Vertex_handle v);}