In Common Lisp, the single colon (a:b) accesses an exported (public) symbol, while the double colon (a::b) accesses an internal (private) symbol in package a.Key DifferencesSyntaxTarget Symbol VisibilityReader Behavior if Not ExportedEncapsulation Intenta:bExternal (Exported)Signals a reader error (package-error)Public API interfacea::bInternal (Unexported)Reads the symbol, or interns it if it d..