Torpor is regulated, not a passive collapse

The low-metabolic torpor state is itself a REGULATED attractor, not a passive floor. Settling under a torpor drive gives a defended low setpoint (-1.2490); pushing the state further down is actively corrected back to it (True). Torpor is defended low metabolism, not loss of control.

RH2. Bistability (previous chapter) plus active regulation of the LOW state (here) together describe hibernation: the organism flips into a distinct basin AND defends a setpoint there. Mechanism [V]; the torpor setpoint depth is [L]; absolute body temperature and metabolic rate are [O].

A defended low setpoint

The torpor basin behaves like the euthermic one in miniature: it has a position the loop returns to after a perturbation. A hibernating animal that drifts too cold rewarms toward its torpor target rather than continuing to fall -- the basin pulls it back.

Two regulated states, one loop

So the same R19 loop offers two defended setpoints -- euthermic and torpid -- separated by the spinodal. Hibernation is moving between them, not abandoning regulation. This is the cleanest statement of why torpor is controlled physiology and not hypothermic failure.