Definition of a Material

A material is defined with the lines:

materialno = materialset.define (number, type)
materialno = materialset(number)
materialno.put(param, value)
materialno.depend(param, fct, Key(Lock)))
...

`number`	number of the material (must be unique)
`type`	type of material (for example `EvpIsoHHypoMaterial`) - see Materials
`param`	code of the material parameter (for example `MASS_DENSITY`, or number of an evolution law such as `YIELD_NUM`, see General Points)
`value`	value of the corresponding material parameter
`fct`	function which characterizes the dependency of the property (optional: no `fct` if no dependency)
`Lock`	Lock which defines the dependency variable of the property (compulsory if there is a dependency)