GENSYM is Harder than You Think

How does one implements GENSYM^[1] in a robust and thread safe way? What if several programs have to interchanged generated SEXPs, so that symbols wont clash? Say two different compilers gensyming assembly output may produce clashing identifiers.

[1] http://www.ai.mit.edu/projects/iiip/doc/CommonLISP/HyperSpec/Body/fun_gensym.html

gynsym