
global - access to a net variable

Calling sequence:
global(identifier)
global(identifier, expr)

Parameter:
identifier   --  identifier
expr         --  expression

Summary:

global(identifier) reads-out the value from the net variablewith the
name identifier and returns it as the result. If the net variable with this
name has no value then the function returns the function call. Not evaluated,
identifier is considered as the name of the net variable.

global(identifier, expr) assigns the value expr to the net variable with
the name identifier.  Although expr is evaluated before the assignment,
without evaluation identifier is considered as the name of the net variable.
global is a kernel function.

