'Keep definition, change category': a practical approach to monadic model evolution

José Nuno Oliveira

Departamento de Informática
Universidade do Minho

Thursday, 21 April 2016, 14:00
Cybernetica Bldg (Akadeemia tee 21), room B101

Slides from the talk [pdf]

Abstract: Faced with the need to quantify software (un)reliability, the semantics of state-based systems is evolving towards quantified (e.g. probabilistic) nondeterminism. In a monadic setting, this calls for "stacking" of monads capturing the various semantics aspects involved, adding complexity to system models.

This talk addresses a particular situation in which such an evolution is undertaken without sacrificing the simplicity of the original (qualitative) definitions, by keeping quantification implicit rather than explicit.

The approach is a monad-monad lifting strategy whereby definitions can be preserved provided the semantics moves to another category. This will be illustrated by showing how to introduce probabilism in an existing software component calculus, by investing on a suitable category of matrices and using linear algebra in the reasoning.

Tarmo Uustalu
Last update 21 April 2016