Adjust to the moving target called the C++ standard. Apparently nowadays it's not allowed to define an explicit copy constructor but not an assignment operator. Consequently, defining the explicit copy constructor in terms of the implicit/automatic assignment operator for general convenience no longer works. Add assignment operators. Caution: not tested with the IBM compiler, but there's no particular reason it shouldn't work.

dsl-2.syn(544-5): Warning: Missing reduction procedure, R183
dsl-2.syn(545-5): Warning: Missing reduction procedure, R184
dsl-2.syn(610-5): Warning: Missing reduction procedure, R211
dsl-2.syn(1396-2): Warning: Conflicts resolved by precedence rules
dsl-2.syn(1396-2): Warning: Keyword anomalies found
Exit 0