@article( MitchVis,author="Mitchell, J.C. and Viswanathan, R.", Title="Standard ML-NJ weak polymorphism and imperative constructs", journal="Information and Computation", volume="??", Year="1995", pages="??", Note="Submitted to special issue on {\it LICS 93.} A preliminary version appeared as M. Hoang, J.C. Mitchell and R. Viswanathan, Standard ML-NJ weak polymorphism and imperative constructs, in {\it Proc. IEEE Symp. on Logic in Computer Science,} 1993, 15--25." )