evVarsOfTerm (EvCast tm co)       = evVarsOfTerm tm `unionVarSet` coVarsOfTcCo co
evVarsOfTerm (EvCast tm co)       = evVarsOfTerm tm `unionVarSet` coVarsOfTcCo co
evVarsOfTerm (EvCast tm co)       = evVarsOfTerm tm `unionVarSet` coVarsOfTcCo co