Fabio Gadducci Alberto Lluch-Lafuente Andrea Vandin Counterpart Semantics for a Second-Order μ-Calculus. 177-205 2012 118 Fundam. Inform. 1-2 http://dx.doi.org/10.3233/FI-2012-709 db/journals/fuin/fuin118.html#GadducciLV12