**Speaker: **John Butcher (University of Auckland)

**Title:** Order of multivalue-multistage methods

**Description: **A “general linear method” is an s-stage, r-value method characterised by a partitioned (s + r) × (s + r) matrix. This includes the classical linear multistep and Runge–Kutta methods and it has been natural to base error analysis and asymptotic order on these well-studied models.

This talk will review the established approaches to defining and analysing the order of general linear methods, with emphasis on B-series analysis, based on an arbitrary starting method. It will be shown that this can be rewritten in terms of two simple algorithms in which the actual starting method is eliminated from the calculations.