3CINT is a (somewhat misleading) acronym for C++ INTerpreter. While CINT will correctly execute a lot of C++ code, there is legal C++ code that is not legal CINT and there is legal CINT that is not legal C++. There is also code that is legal in both C++ and CINT but that does subtly different things in the two environments. Therefore it is more correct to say that the CINT language shares a lot of syntax with C++, not that it is C++.