Type reconstruction with recursive types and atomic subtyping [chapter]

Jerzy Tiuryn, Mitchell Wand
1993 Lecture Notes in Computer Science  
We consider the problenl of type reconstruction for )~-terms over a type system with recursive types and atomic subsumptions. This problem reduces to the problem of solving a finite set of inequalities over infinite trees. We show how to solve such inequalities by reduction to an infinite but well-structured set of inequalities over the base types. This infinite set of inequalities is solved using Biichi automata. The resulting Mgorithm is in DEXPTIME. This also improves the previous NEXPTIME
more » ... per bound for type reconstruction for finite types with atomic subtyping. We show that the key steps in the algorithm are PSPACE-hard.
doi:10.1007/3-540-56610-4_98 fatcat:ohkega6jgrabnjmw3bddjrez7q