Halliday & Matthiessen (2014: 442):
This is where what is being linked by a logico-semantic relation is not a single clause but rather a ‘sub-complex’ — a clause nexus in its own right. …
We can show nesting in either of two ways.
- (i) The nesting can be represented explicitly as internal bracketing — eg 1 ^ 2 (α ^ β);
- (ii) or it can be represented as a simple string — eg 1 ^ 2α ^ 2β.