A person is said to cause an effect "voluntarily" when he causes it by means whereby he intended to cause it, or by means which, at the time of employing those means, he knew or had reason to believe to be likely to cause it"
Illustration
A sets fire, by night, to an inhabited house in a large town, for the purpose of
facilitating a robbery and thus causes the death of a person" Here, A may not
have intended to cause death; and may even be sorry that death has been caused
by his act; yet, if he knew that he was likely to cause death, he has caused
death voluntarily"
32 IPC Words referring to acts include illegal omissions
34 IPC Acts done by several persons in furtherance of common intention
36 IPC Effect caused partly by act and partly by omission
37 IPC Co-operation by doing one of several acts constituting an offence
38 IPC Persons concerned in criminal act may be guilty of different offences