On 22 Mar 2017, at 16:05, Buesing, Henrik <HBuesing@eonerc.rwth-aachen.de> wrote:

This is not the correct syntax anymore. How do I say nest=False today?

You never w set this as an option in the solver parameters. Say "mat_type": "aij"

See http://firedrakeproject.org/solving-interface.html#id11 for more information.

Lawrence