Ross indexed the following pages under the keyword: "Critical surface".

Break surface Critical surface defined 0897 0898

Break surface Critical surface if not related to essential variables Summary: "Step-function" is defined. An analytic formula given for one. If a function in a substitution is a step function of the variables, the corresponding variable in the solved equations is a step-function of the time. The effect in a field of a step-function is discussed, The essential conditions for a break are a cloud of dots, each of which has a number associated with it saying "change one of the step-functions to this new value" and not a surface as suggested on 898. 1003 1004

Critical surface if not related to essential variables Neutral point (of equilibrium - including 'cycle', 'region' etc.) examples Summary: The behaviour of break-surfaces. 1021 1022

Critical surface if not related to essential variables Critical surface interactions Summary: An example is given, in all detail, of a substitution with two step-functions. It confirms the theorum of 1021. The existence of "false neutral points" is noted. Neutral point (of equilibrium - including 'cycle', 'region' etc.) "false" 1027 1028

Summary: Later we shall have to show how we can break down the minute rigidity of our dynamic systems, where the minutest change has to be put in and may lead to something profoundly different. Suggested way of doing it. Break surface no free edge Critical surface has no free edge Summary: The V-surface of a step-function cannot have a free edge. Group (mathematical) finite continuous 1043 1044

Break surface further properties Critical surface if not related to essential variables Summary: A clarification of the concept of a "break-surface". Summary: The conditioned reflex is not clear yet. Reflex, conditioned and break-theory 1175 1176

Summary: Allbutt on a type of man. Essential variables sometimes not related to critical states Critical surface if not related to essential variables Pain patient insensitive to pain 2831 2832

Summary: Additive mechanisms in the brain. 5763, 5765.1, 5766.1, 5768 Cortex as store Critical surface variation of Signal in ultrastable system 5760 5761