Halliday & Matthiessen (1999: 148):
If the process is creative, the outcome is that some entity comes into existence: such a figure may be construed as a doing with effectum, as in he baked a cake; but it may simply be a creative happening such as icicles formed. In either case the outcoming figure is one of being (more specifically, existing):he baked a cake outcome: ‘there exists a cake’icicles formed outcome: ‘there exist icicles’