“(1) insection 2 of the Homicide Act 1957 (persons suffering from diminished responsibility), for sub-section (1) substitute “(1) A person (“D”) who kills or is a party to the killing of another is not to be convicted of murder if D were suffering from an abnormality of mental functioning which - (a) arose from a recognised medical condition – (b) substantially impaired D’s ability to do one or more of the things mentioned in sub-section (1A), and (c) provides an explanation for D’s acts and omissions in doing or being a party to the killing. (1A) those things are – (a) to understand the nature of D’s conduct; (b) to form a rational judgment; (c) to exercise self-control.””