J. B. Wells, Allyn Dimock, Robert Muller, and Franklyn Turbak. 
<b>A Calculus for Polymorphic and Polyvariant Flow Types.</b>
<i>Journal of Functional Programming</i> 12(3): 183-227, May 2002.<hr>We present &lambda;<sup>CIL</sup>, a typed &lambda;-calculus which serves as the foundation
for a typed intermediate language for optimizing compilers for
higher-order polymorphic programming languages.  
The key innovation of &lambda;<sup>CIL</sup> is a novel formulation of intersection and union types 
and flow labels on both terms and types.  
These <i>flow types</i> can encode polyvariant
control and data flow information within a polymorphically typed
program representation.  Flow types can guide a compiler in generating
customized data representations in a strongly typed setting. 
Since &lambda;<sup>CIL</sup> enjoys confluence, standardization, and subject reduction 
properties, it is a valuable tool for reasoning about programs 
and program transformations.<hr>[<a href="jfp02.ps">PS</a>]  [<a href="jfp02.pdf">PDF</a>]