Summary: Type-Based Termination for Dependent Types
INRIA, Team r2
PPS Lab, Paris
INRIA Saclay, Parc Orsay Universit´e, Paris, France
19 March 2010
Andreas Abel (INRIA) Type-Based Termination ProVal '10 1 / 17
View data (natural numbers, lists, binary trees) as trees.
Type of data is equipped with a size.
Size = upper bound on height of tree.
Size must decrease in each recursive call.
Termination is ensured by type-checker.
Andreas Abel (INRIA) Type-Based Termination ProVal '10 2 / 17
Sized types in a nutshell
Sizes are upper bounds.