Ticket #31 (new task)

Description

Many things are currently expressed as dotted methods but ought to be functional methods. The obvious ones that come to mind are:

• Equality: we should just have opr = as a functional method rather than dotted .eq()
• IN: this calls through to the contains method. Get rid of contains and replace it with opr IN as a functional method.
• Transpose: replace .t() with opr (self)^{T and/or opr (self)}*.
• Arithmetic: this is waiting for the cleanup of primitive types.

This is a suitable project for newcomers looking for something useful to contribute, and wanting to get up to speed with the language at the same time.