Table 2.

Overview of various possible threads' models. (Threads can be assumed to charge under compression or extension, and they can provide the prong with a pull or a push. Compress–pull and extend–push models are equivalent. Similarly, a compress–push model is equivalent to an extend–pull one.)

	H(iϕ − σ)	H(−iϕ − σ)
β > 0	compress–pull	extend–pull
β < 0	compress–push	extend–push