This International Standard specifies syntax and semantics of the computer programming language ISLisp by specifying requirements for a conforming ISLisp processor and a conforming ISLisp text. This International Standard does not specify: (a) the size or complexity of an ISLisp text that exceeds the capacity of any specific data processing system or the capacity of a particular processor, nor the actions to be taken when the corresponding limits are exceeded; (b) the minimal requirements of a data processing system that is capable of supporting an implementation of a processor for ISLisp; (c) the method of preparation of an ISLisp text for execution and the method of activation of this ISLisp text, prepared for execution; (d) the typographical presentation of an ISLisp text published for human reading; (e) extensions that might or might not be provided by the implementation.